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Agriculture 
Canada 



PUBLICATION 1635 



GROWING DEGREE- 
AND CROP PRODUCTION 
IN CANADA 



TABLE 



FREQUENCY CLASSES AND 30-YEAR AVERAGES OF DEGREE DAYS ABOVE 10°C 



CLASS FREQUENCY AND BOUNDARY 



530.4 

C212 

P1635 

1977 

(1989 pritn) 

c.3 



RECORD 










RECORD 


DAILY 


-OWMB 


B 


NORMAL 


A 


MA 


HIGH 


MEAN 














1 


7 


1 











1 


4 


10 


1 











2 


2 


^Hc^^l 


3 





1 


2 


6 


12 


36 


6 


1 


2 


8 


10 


17 


39 





4 


6 


12 


21 


3i 


49 


19 


7 


14 


23 


35 


54 


HEE^H 


31 


11 


27 


39 


54 


67 


87 


48 


15 


52 


69 


81 


99 


126 


73 


34 


75 


91 


104 


137 


164 


102 


77 


103 


120 


136 


177 


206 


134 


107 


139 


156 


180 


228 


267 


175 


145 


181 


211 


233 


266 


316 


223 


218 


233 


271 


288 


321 


375 


279 


271 


287 


319 


346 


390 


440 


335 



Agriculture Canada Publication 1635/E 

available from 

Communications Branch, Agriculture Canada, 

Ottawa K1A0C7 

°Minister of Supply and Services Canada 1977 
Cat. No. A53-1 635/1 977E ISBN: 0-662-01 138-4 
Printed 1977 Reprinted 1989 3M-8:89 

figalement disponible en franc, ais sous le titre 
Degrts-jours de croissance et production des 
cultures au Canada. 



FOREWORD 

In 1959, the Canada Department of Agriculture released the 
publication entitled Heat Units and Crop Growth, which proved to 
be extremely popular and was reprinted several times. 

The authors, R. M. Holmes and G. W. Robertson, reviewed 
the concept of "heat units" or "degree-days" and introduced a 
generalized formula for computing normal degree-days based on 
mean monthly temperatures. The publication included several 
practical applications of degree-days, showing how long-term 
climatic data can be used in day-to-day agricultural operations. 
Many of these applications have been included in the revised text, 
because they so aptly demonstrate the degree-day concept. 

The theory that a direct relationship exists between temper- 
ature and the rate at which a plant grows and develops is not new, 
but it remains viable. So do the methods for defining this relation- 
ship quantitatively. For this reason, the decision was made to up- 
date the original publication using the climatic records for the cur- 
rent 30-year period. Another purpose is to introduce the Celsius 
temperature scale in the calculation and application of degree- 
days. We hope that the revised presentation proves to be as useful 
as the original, and equally applicable to the present-day agricul- 
tural scene in Canada. 



Digitized by the Internet Archive 

in 2012 with funding from 

Agriculture and Agri-Food Canada - Agriculture et Agroalimentaire Canada 



http://www.archive.org/details/growingdegreedayOOcana 



GROWING DEGREE-DAYS AND 

CROP PRODUCTION 

IN CANADA 



S. N. EDEY1 

Land Resource Research Centre 
Ottawa, Ontario 



INTRODUCTION 

Plants require energy to grow and develop, and some of this 
energy is in the form of heat. The heat required is expressed as 
degrees of temperature. Many meteorological elements influence 
the well-being of a plant, but temperature is the single most im- 
portant factor contributing to plant response. Because of this fact, 
and because information on air temperatures is readily available, 
many attempts have been made to link plant response to some 
function of temperature. 

Thus the concept of degree-days or heat units has evolved, 
and it is now widely accepted as a means to relate plant growth, 
development, and maturity to temperature. The concept assumes 
that each plant has its own particular base or threshold tempera- 
ture below which growth does not occur. The amount of heat 
accumulated during the day, as obtained by subtracting the plant's 
base temperature from the mean temperature for the day, is termed 
the degree-day accumulation. Degree-days may be accumulated 
for a week, for a month, or until plant maturity is reached. 

TEMPERATURE 

Most agricultural crops grow in conditions where the temper- 
ature fluctuates widely. Cool nights and warm days are usually 
favorable to crops. For example, certain varieties of tomatoes set 
fruit only when the night temperature is near 18°C. Consequently, 
these tomatoes are not grown commercially in the tropics where 



1 Retired 1988. Contact Mr. A. Bootsma for further information. 



nights are usually warmer, or in the field in northern areas where 
night temperatures are too cool. Tomato yields are reliable in areas 
where maritime-type conditions keep temperatures consistently in 
a favorable range during the growing season. In other areas, pro- 
duction may be very variable. 

Peas do best when daytime temperatures stay below 27°C; 
above 30°C, growth is markedly poorer. 

Onions flower only under low night temperatures, but higher 
temperatures are required for other growth processes. 

Potatoes set tubers best when temperatures during the night 
fall to between 10° and 14°C. Therefore, more northern regions 
like the Maritimes, northern portions of the United States, and 
Ireland are best suited to potato production. 

Temperature regulates many of the physical and chemical 
processes within a plant, which in turn control the rate of growth 
and development toward maturity. Certain temperatures are con- 
sidered critical to the well-being of the plant and these include 
minimum, maximum, and optimum values. The maximum temper- 
ature for plant life is about 54°C and the minimum temperature 
for growth is about 5°C. However, these values vary according to 
the particular cultivar, the stage of growth, and the conditioning of 
the plant. In plants of the temperate zone, the optimum tempera- 
ture for seed germination is usually less than the temperature most 
suitable for growth, which in turn is often lower than the tempera- 
ture most suitable for flowering and fruiting. 

It may be difficult to see how any relationship could be for- 
mulated to express the overall growth of a plant from planting to 
maturity. However, chemical and physical processes, such as the 
chemical reactions that increase their rate as the temperature in- 
creases, are subject to the same laws whether they take place 
within a plant or elsewhere. 

OTHER ENVIRONMENTAL FACTORS 

Several other environmental factors influence the growing 
degree-day relationship and may cause variation within a crop. 
They are described below. 

Soil fertility level 

Low soil fertility causes slow growth. A high nitrogen level sup- 
ports heavy stem growth and thus delays maturity. A high phospho- 
rus level tends to hasten maturity. 

Plant population 

A low plant population matures slightly earlier than a denser popu- 
lation, provided weeds do not make up the difference. 



Soil type 

Sandy soils warm up earlier than clay soils. Other factors such as 
the fertility status and moisture characteristics are associated with 
soil type. 

Soil temperature 

During the spring warm-up, soil temperature lags appreciably 
behind air temperature. Hence, if degree-days are accumulated on 
the basis of air temperature, the resulting totals may be too high. 
Soil temperature readings can be used instead, until plant emer- 
gence. Southern slopes warm up sooner in spring than northern 
slopes. Seeds planted deep are cooler and usually emerge later 
than those planted shallow, provided moisture is not lacking. 

Soil moisture 

Poorly drained soils are cold and also give rise to a variety of 
nutritional problems. If moisture is lacking at seeding time or during 
early growth, maturity is delayed even though the number of 
degree-days has been building up. Drought during the latter part of 
the life span of plants usually hastens maturity, or the plants may 
even die before they reach maturity. 

Photoperiod 

Regional variation in a particular crop is usually attributed to 
variation in the length of photoperiod (day length). Longer periods 
of daylight reduce the heat requirement of many crops, particularly 
those that thrive in cool weather. However, degree-day accumula- 
tions seem to provide fairly accurate guidelines without adjustment 
for photoperiod at any one location, because daylight hours do not 
vary much during the life span of most crops in the temperate zone. 
In other zones or fringe areas in the north, the duration of daylight 
may have to be considered. Some plants mature more rapidly in the 
north where days are long in the summer than would be expected 
from temperature accumulation alone. 

USES OF THE DEGREE-DAY CONCEPT 

Despite limitations, the growing degree-day concept is 
effective and is often used by growers and processors to schedule 
planting and subsequent harvesting of many cash crops, particularly 
peas, beans, and sweet corn. The concept provides a reliable index 
of the progress of these crops. Information on degree-days can be 
used to predict the yield and oil quality of soybeans and other 
legumes. It helps to identify the limits of geographical areas suitable 
for production of various crops, particularly corn, and to evaluate 
areas agriculturally suitable for new or non-native plants. Other 



applications of degree-days include the prediction of bloom date, 
tree fruit development, and insect activity related to agriculture and 
forestry. 

Because we are adapting the metric system of measurement 
in Canada, all data values, tabulations, and graphs are based on 
the Celsius temperature scale. Previously calculated Fahrenheit 
degree-day accumulations could be converted by multiplying them 
by 5/9, but it would not be helpful to do so. The old and new data 
series cannot be directly compared because they are not exactly 
equivalent. For instance, 5°C has replaced 42°F (5.556°C) as a 
base value. Therefore, it is better to recompute growing degree- 
days from the original observational data. 

COMPUTATION OF GROWING DEGREE-DAYS 

Temperature affects plant processes mainly by controlling the 
rate of growth. It may prevent growth from taking place at all. 
There are certain minimum temperatures below which plants do 
not grow, and the actual minimum depends on the particular plant 
involved. For general plant growth, a base or threshold temperature 
of 5°C is probably most valid; however, many crops have been 
assigned their own base or threshold values. The values have been 
determined by experiments and field trials; some average values are 
given in Table 1 . 



TABLE 1 . 


AVERAGE BASE TEMPERATURE VALUES 




FOR SELECTED CROPS 




Crop 




Base temperature 
°C 


Spinach 




2.2 


Lettuce 




4.4 


General plant growth 


5.0 


Peas 




5.5 


Asparagus 




5.5 


Corn 




10.0 


Beans 




10.0 


Pumpkins 




13.0 


Tomatoes 




13.0 





In practice, the concept of growing degree-days assumes that 
plant growth is related directly to the average daily temperature. 
It ignores soil temperature, difference in the pattern of night and 
day temperatures, and other variations caused by the stage of 



8 



growth. The degree-days for each day are added together, or 
accumulated, throughout the growing season. To compute growing 
degree-days for a particular crop on a particular day, you first cal- 
culate the daily mean temperature by averaging the maximum 
(highest) and the minimum (lowest) temperatures for the day. 
Then you subtract the specific base temperature for the crop or 
plant in question from the mean temperature. This gives the number 
of growing degree-days for the 24-hr period. 

Example: 

Maximum temperature (°C): 30 
Minimum temperature (°C): 18 
Mean temperature (°C) = Max. + Min. = 24 



Growing degree-days at base 0°C = 24 — =24 
Growing degree-days at base 5°C = 24 — 5 =19 
Growing degree-days at base 13°C = 24— 13= 1 1 

If the daily mean temperature is equal to or less than the base 
temperature, the degree-day value is zero. Negative values are not 
used in the calculation, because little or no growth takes place on 
days when the average temperature is less than the base tempera- 
ture for the crop. 

The number of degree days a crop normally takes to mature 
depends largely on the plant and the variety being grown. A parti- 
cular plant or variety may have a rather specific requirement for 
total heat accumulated through the growing season to reach 
maturity. This amount is called the heat maturity constant (HMC); 
it is also referred to as the summation constant, the varietal index, 
or the remainder index. The corn hybrids frequently grown today 
need from 800 to 1800 degree-days (their maturity constants) to 
produce 30% kernel moisture at maturity. 

Although the concept is not without problems, the accumula- 
tion of growing degree-days is a more precise way of predicting 
crop maturity than simply counting the passing days. If you have a 
week of mean temperatures below the base value, your crop is not 
growing, and so it is not a week nearer to maturity. Similarly, on 
days when temperatures exceed the maximum growth value, trans- 
piration becomes too high and the resulting moisture stress to the 
plants delays their growth. 

Data on degree-days or their seasonal accumulations are often 
difficult to obtain, so researchers have used long-term climatolo- 
gical records to work out relationships between mean temperatures 
and degree-days. The relationships can be universally used to 
calculate degree-days above any base temperature. One such 



formula provides an estimate of the normal number of degree-days 
accumulated for any one month; the equation is as follows: 

DD = N [ (t-b)+L(x, A/] 
where DD is the normal degree-days for the month, N is the 
number of calendar days in the month, t is the monthly mean tem- 
perature, b is the base temperature, a is the standard deviation of 
the monthly mean temperature, and L is the proportionality co- 
efficient. The standard deviation expresses the probable variation 
of the monthly mean temperature from the long-term normal value. 

Although DD is a monthly value, daily values can be obtained 
by plotting the calculated monthly values at the midpoint of each 
month, and joining these points. The daily values can then be read 
off the graph. For this method, both the monthly mean temperature 
and the standard deviation of the mean are required for the calcula- 
tions. Ordinarily, this type of information can be readily obtained 
from published climatological data. The values for the proportion- 
ality coefficient L are obtained from the table given in Appendix I. 

Several variations of the growing degree-day concept have 
evolved over the years, each one attempting to calendarize crop 
growth and development. One of the most widely used in Canada 
is the corn heat unit (CHU). A physiological type of index, it accu- 
mulates heat units or degree-days from the average date in the 
spring when a mean temperature of 12.8°C occurs to the date when 
there is a 10% chance of a 0°C freeze in the fall. The index itself 
uses the following equation for calculating the heat or degree-day 
units: 
CHU = 1.80(r M N-4.4)+3.33(r MX -10.0)-0.084(r MX -10.0) 2 

~2~ 

where the values for 7" MN and 7" MX are the average minimum and max- 
imum temperatures for the day. 

DISCUSSION AND APPLICATION OF GROWING 

DEGREE-DAYS 

Long-term temperature records can be used to estimate heat 
accumulation so that the probable date of maturity of a crop can 
be predicted. On a graph, the curve for normal growing degree-day 
(GDD) accumulation based on these records is a gradual one; it 
is nearly flat in the spring during cool weather and rises more 
sharply during the summer when heat is rapidly accumulated (as 
illustrated by the graphs in this publication) . 

To predict the harvest date of an individual crop, the normal 
GDD accumulation curve is used starting from the day of planting. 
The expected harvest date may have to be adjusted as the season 

10 



progresses, if the temperature through the growing season varies 
from normality. In that case, the actual daily temperatures are used 
to compute the heat accumulation up to the day when the calcula- 
tion is being done, and the normal curve is then used for the re- 
mainder of the season. A surplus or deficiency of degree-days either 
hastens or delays the harvest from its predicted date. 

For example, suppose you plant a cash crop in the Ottawa 
area on May 15 (Fig. 1 ). The crop planted has a base temperature 
of 10°C and requires 1050 GDD to reach maturity. On the graph 



2200 



2000 



1800 



1600 - 



1400 

> 
< 
Q 

"J 1200 
ill 

oc 
o 



1000 



800 



600 



400 



200 




10 J C 



"i-r 

5 10 1620 25 

APRIL 



Fig. 1. Application of average seasonal growing degree-day accumulations (10°C 
base temperature) and average freeze dates of a given severity for Ottawa. 



11 



for the Ottawa area you follow the curve for the 10°C base temper- 
ature starting at May 15, when 80 GDD have elapsed, for a further 
1050 GDD (to the point on the curve at 1130 GDD). This brings 
you to a predicted maturity date of September 22 if conditions are 
normal. However, if at midseason, say August 1, you wish to 
verify your original estimate, you must total the number of growing 
degree-days actually accumulated to August 1 from the planting 
time of May 15. In our example (Fig. 1) this value, 660 GDD, is 
slightly below the normal for August 1 , which is 720 GDD. Starting 
at 660 GDD on August 1, you draw a line parallel to the normai 
seasonal accumulation curve, continuing for a further 390 GDD to 
reach the required 1050 GDD from the time of planting. (The point 
on the graph is again 1130 GDD, because of the 80 GDD elapsed 
before planting). This brings you to a new maturity date of Sep- 
tember 29. The new date is 7 days later than originally predicted, 
and conditions are now becoming hazardous to the crop because 
there is a 50% chance of a freeze on or after September 28 in the 
Ottawa area. 

It is difficult to plant a series of fields so that the whole crop 
does not mature at the same time. However, if planting is done in 
proportion to degree-day accumulation, a fairly orderly harvest can 
be arranged. If the normal daily heat accumulation at harvest is 
20 GDD, and the capacity of the cannery at harvest is 24 ha/day, 
then the ratio of heat accumulated at harvest to the number of 
hectares harvested a day is 20:24, or 1:1.2. {For calculations in 
acres, if the cannery capacity is 60 ac/day, the ratio is 20:60 or 
1:3.) Therefore, after the accumulation of each degree-day at 
planting time, 1 .2 ha (3 ac) should be planted; after 10 degree-days 
have accumulated, 12 ha (30 ac) may be planted. Strict adherence 
to this ratio, however, might result in serious delays in planting 
during a cool spring. In that case, more fields would have to be 
planted than warranted by the heat accumulated. The method would 
forecast the time when a heavy influx of crops would occur at the 
cannery. 

If several fields scattered over an area were planted with peas 
on the same day, they would not all mature at the same time. 
Experience has shown that harvest would normally be spread over 
2 or 3 days because of the environmental factors previously 
mentioned. Therefore, it is common practice to plant two or three 
times as many hectares on the first day as would normally be done 
according to the degree-day accumulation. 

Let us suppose four varieties of peas are to be planted; each 
covers a different area and has a different heat maturity constant, 
as follows: 

12 



Variety Area HMC (°C) 

ha (ac) 

Alaska 160(400) 680-710 

Sweets 80 (200) 720-750 

Perfection 120(300) 830-860 

Superior 120(300) 890-920 

Assume that the normal daily heat accumulation at harvest 
time is 20 degree-days and that the cannery has the capacity to 
process 1 6 ha {40 ac) of crop a day. The planting ratio is 16 ha 
(40 ac) for every 20 degree-days accumulated, or 0.8:1 (2:1). Be- 
cause 160 ha (400 ac) of Alaska peas are desired, the planting 
would normally be spread over 200 degree-days. However, the 
heat maturity constant varies between different fields, so three 
times the normal area should be planted during the first 20 degree- 
days accumulated. Thus, 48 ha ( 120 ac) of Alaska peas are planted 
during the first 20 degree-days and 1 12 ha (280 ac) during the next 
140 degree-days. The last 1 1 2 ha (280 ac) are planted according 
to the normal planting ratio. 

After the accumulation of 680 degree-days, the first Alaska 
peas enter the cannery and the crop continues to come in for 10 
days, because the crop is on 160 ha (400 ac) and the capacity of 
the cannery is 16 ha (40 ac) a day. Two hundred degree-days 
normally accumulate during the 10-day harvest. The total degree- 
day accumulation from the first plantings to the last harvest of 
Alaska peas then is 680 + 200 = 880. 

At this time, early Sweets peas must be ready for harvesting. 
They require 720 degree-days to mature, so planting must begin 
880 — 120— 1 60 degree-days after the first Alaska planting. Because 
80 ha (200 ac) are required and the planting ratio is 0.8:1 (2:1), 
planting is distributed over 80/0.8 (200/2) = 100 degree-days. 

The time required for processing is determined by the variation in 
degree-days to maturity of the peas, rather than cannery capacity. 
Late Sweets peas require 750 degree-days to mature, so the pro- 
cessing time of Sweets from earliest to latest is extended by 
750 — 720 = 30 degree-days. Therefore, total heat accumulation 
from first planting of Alaska peas to the last processing date of 
Sweets is 880+100 + 30 = 1010 degree-days. 

At this time Perfection peas must be ready for processing. 
The same calculations as for Sweets peas are performed to obtain 
the planting and processing times for Perfection peas, and again 
for Superior peas. 

After some experimenting and adjustment for local peculiar- 
ities, the degree-day theory can be a reliable tool for both farmers 

13 



and processors. This theory is not meant to replace any practice 
already in use in field operations. It is rather an attempt to express 
mathematically the influence of temperature on crop growth. Many 
commercial canners have found this method of scheduling plant- 
ings very useful. 

The heat maturity constant (HMC) (the number of growing 
degree-days from planting to harvest) is often difficult to find out 
for specific crop varieties. It is hoped eventually that all companies 
will put the HMC value on the seed tag or package. This practice is 
common for hybrid corn varieties. 

Growing degree-day data for 1 1 stations across Canada are 
presented in both tabulated and graphic forms, in Tables 2-32 and 
Figures 2-12. The tabulated data have a particular format that re- 
quires some explanation. Data collected over 30 years, 1941 to 
1970 inclusive, have been arranged in a frequency table. The tables 
consist of six columns that indicate ranges or "octiles" and one 
column that gives the average or mean value for the week ending 
on the date specified. The first column, designated by Record low, 
gives the lowest number of degree-days ever recorded during the 
30-year period; similarly, the sixth column gives the highest number 
of degree-days ever recorded. 

Columns 2, 3, 4, and 5 are referred to as the first, third, fifth, 
and seventh octile. This means that if similar conditions prevail in 
the future, one could expect values below the first octile to occur 
one-eighth of the time, values below the third octile, three-eighths of 
the time, and so on. 

Other information can be derived from the tables. Each inter- 
val between two columns (the spaces under the headings MB, B, 
Normal, A, and MA) gives a range of degree-day values. The first 
range is designated MB, for much below normal; it is followed by 
range B, for below normal; range Normal; range A, for above nor- 
mal; and range MA, for much above normal. All ranges except MB 
and MA each contain one-quarter of the total range of values; 
ranges MB and MA each contain one-eighth. Such a system enables 
the grower or farmer to compare the current growing season with 
a normal season and determine just how late or early are the pre- 
sent growing conditions. 

For example, the following information was taken from Table 
23 for Ottawa and shows the normal distribution of degree-days for 
the week ending August 5. The base temperature is 5°C. 

14 



Record Record 

low MB B Normal A MA high Mean 

1055 1162 1227 1300 1374 1502 1266 

(1st (3rd (5th (7th 

octile) octile) octile) octile) 

Range Range Range Range Range 

MB B Normal A MA 

(much (below (above (much 

below normal) normal) above 

normal) normal) 



Thus, if the accumulated growing degree-days for August 5 
are said to be a record high, or another such designation, then the 
meaning, in terms of degree-days and likelihood of occurrence, is 
as follows: 

Record high — the value is equal to or greater than 1502 

MA (Much above — the value is greater than 1374 but less than 
normal) 1502, and should occur one-eighth of the 

time 

A (Above normal) — the value is greater than 1300 but equal to or 

less than 1374, and should occur one-quarter 
of the time 

N (Normal) — the value is equal to or between 1227 and 

1300, and should occur one-quarter of the 
time 

B (Below normal) — the value is less than 1227 but equal to or 

greater than 1162, and should occur one- 
quarter of the time 

MB (Much below — the value is less than 1162 but greater than 
normal) 1055, and should occur one-eighth of the 

time 

Record low — the value is equal to or less than 1055 

Mean — the value is the average or arithmetic mean 

for the 30-year period 

Although a few growing degree-days accumulate before the 
month of April, no direct contribution is made to the beginning of 
growth in early spring. Consequently, the tabulated accumulations 

are given only for those months normally considered to be part of 

15 



the growing season in Canada. This period extends from April 
through to the end of October. 

In the graphic presentation of accumulated growing degree- 
days, curves are shown for three of the most commonly used base 
temperatures, 5, 10, and 13°C. By plotting the growing degree-days 
for the current season, as derived from local temperature data, you 
can evaluate the current season's progress in relation to the normal 
or expected temperature pattern. Similarly, comparisons can be 
made between geographical areas that may each be characteristic 
of a particular climate in a certain region of Canada. Such climates 
may reflect, individually or in combination, the modifying effects of 
large areas of land or water and latitude. For example, Harrow, 
Ont., and Beaverlodge, Alta., exhibit quite different climates. Al- 
though the difference is mainly a result of latitude, the proximity of 
water, the air drainage pattern, and the soil type also influence the 
particular temperature regime and this in turn determines the avail- 
ability of growing degree-days. 

In addition to the availability of growing degree-days, the 
length of the freeze-free period influences the crop production of a 
region. This period is defined as the number of calendar days from 
the average date of the last freeze (0°C) in the spring to the 
average date of the first freeze (0°C) in the fall. The days of the 
last spring freeze and the first fall freeze are not included in the 
total freeze-free period because they are days with a freezing tem- 
perature. 

The average dates of the last spring freeze and the first fall 
freeze at three levels of severity, light (0°), moderate (—2°), and 
severe (— 4°C), are also given on the graphs of accumulated grow- 
ing degree-days for each of the 1 1 stations. These dates provide the 
user with additional insight concerning the risk of a freeze in the 
particular region. 

A large difference exists between the freeze-free periods at 
the various stations; for instance, Sidney, B.C., has an average 
freeze-free season of 230 days whereas Beaverlodge, Alta., has 
only 108 days. It should be noted that although the freeze-free 
season may be longer, the accumulation of growing degree-days is 
not always correspondingly higher. Ottawa, Ont., has a short season 
of 138 days compared with Sidney, B.C., which has a 230-day 
season. However, the accumulated growing degree-days (base 5°C) 
in Ottawa are seasonally more than 2000, whereas at Sidney they 

are seasonally less than 1900. This explains why a "heat-loving" 
crop such as corn does not produce grain particularly well in a 
maritime type of climate such as that found in the coastal region 
of British Columbia. 



16 



Although the growing season is usually assumed to be the 
same length as the freeze-free period, the true growing season can 
be defined as the number of days in a year in which a crop can 
grow. In general, plant growth begins and ends at a threshold tem- 
perature of 5°C, so the growing season can be defined as the num- 
ber of days between the first time that a mean daily temperature of 
5°C occurs in the spring and the last time a mean daily temperature 
of 5°C occurs in the fall. The direct measurement of the length of 
the growing season is extremely difficult because of biological fac- 
tors; such matters as the type of cultivar, stage of development, 
and resistance to low temperature must be considered. Therefore, 
a purely meteorological definition of the growing season is incom- 
plete and should be used with caution in agroclimatic descriptions. 

ACKNOWLEDGMENTS 

This work is based on the climatological records compiled by 
the Atmospheric Environment Service, Department of the Environ- 
ment. A special thanks to those weather observers who diligently 
observe and record the daily weather. Without such long-term 
observations, publications of this nature are impossible. 




17 



APPENDIX I 



THE FACTORS H AND L FOR USE IN COMPUTING 

DEGREE-DAYS 



H 



H 



H 



H 



-0.70 


0.70 


-0.32 


0.39 


0.05 


0.17 


0.42 


0.05 


-0.69 


0.70 


-0.31 


0.38 


0.06 


0.17 


0.43 


0.05 


-0.68 


0.69 


-0.30 


0.38 


0.07 


0.16 


0.44 


0.04 


-0.67 


0.68 


-0.29 


0.37 


0.08 


0.16 


0.45 


0.04 


-0.66 


0.67 


-0.28 


0.36 


0.09 


0.15 


0.46 


0.04 


-0.65 


0.66 


-0.27 


0.36 


0.10 


0.15 


0.47 


0.04 


-0.64 


0.65 


-0.26 


0.35 


0.11 


0.14 


0.48 


0.04 


-0.63 


0.64 


-0.25 


0.34 


0.12 


0.14 


0.49 


0.03 


-0.62 


0.63 


-0.24 


0.34 


0.13 


0.13 


0.50 


0.03 


-0.61 


0.62 


-0.23 


0.33 


0.14 


0.13 


0.51 


0.03 


-0.60 


0.61 


-0.22 


0.32 


0.15 


0.13 


0.52 


0.03 


-0.59 


0.60 


-0.21 


0.32 


0.16 


0.12 


0.53 


0.03 


-0.58 


0.59 


-0.20 


0.31 


0.17 


0.12 


0.54 


0.03 


-0.57 


0.58 


-0.19 


0.30 


0.18 


0.11 


0.55 


0.03 


-0.56 


0.58 


-0.18 


0.30 


0.19 


0.11 


0.56 


0.02 


-0.55 


0.57 


-0.17 


0.29 


0.20 


0.11 


0.57 


0.02 


-0.54 


0.56 


-0.16 


0.29 


0.21 


0.10 


0.58 


0.02 


-0.53 


0.55 


-0.15 


0.28 


0.22 


0.10 


0.59 


0.02 


-0.52 


0.54 


-0.14 


0.27 


0.23 


0.10 


0.60 


0.02 


-0.51 


0.53 


-0.13 


0.27 


0.24 


0.09 


0.61 


0.02 


-0.50 


0.53 


-0.12 


0.26 


0.25 


0.09 


0.62 


0.02 


-0.49 


0.52 


-0.11 


0.25 


0.26 


0.09 


0.63 


0.02 


-0.48 


0.51 


-0.10 


0.25 


0.27 


0.08 


0.64 


0.02 


-0.47 


0.50 


-0.09 


0.24 


0.28 


0.08 


0.65 


0.01 


-0.46 


0.50 


-0.08 


0.24 


0.29 


0.08 


0.66 


0.01 


-0.45 


0.49 


-0.07 


0.23 


0.30 


0.07 


0.67 


0.01 


-0.44 


0.48 


-0.06 


0.23 


0.31 


0.07 


0.68 


0.01 


-0.43 


0.47 


-0.05 


0.22 


0.32 


0.07 


0.69 


0.01 


-0.42 


0.47 


-0.04 


0.22 


0.33 


0.07 


0.70 


0.01 


-0.41 


0.46 


-0.03 


0.21 


0.34 


0.06 


0.71 


0.01 


-0.40 


0.45 


-0.02 


0.20 


0.35 


0.06 


0.72 


0.01 


-0.39 


0.44 


-0.01 


0.20 


0.36 


0.06 


0.73 


0.01 


-0.38 


0.44 


-0.00 


0.19 


0.37 


0.06 


0.74 


0.01 


-0.37 


0.43 


0.01 


0.19 


0.38 


0.06 


0.75 


0.01 


-0.36 


0.42 


0.02 


0.18 


0.39 


0.05 


0.76 


0.01 


-0.35 


0.41 


0.03 


0.18 


0.40 


0.05 


0.77 


0.01 


-0.34 


0.41 


0.04 


0.17 


0.41 


0.05 


0.78 


0.00 


-0.33 


0.40 














For H l 


^0.78, L 


= 0. 












For H^-0.10, 


L--H. 












To obtain a 


value for L, use the 


followi 


ng equation 


to calcu 


ate H: 




H = :(t 


-b) 















ay A/ 

where ? = monthly mean temperature 

6 = base temperature 

a — standard deviation of the monthly mean temperature 

N — number of days in the month 
Reference: Thorn, H.C.S. 1954. The rational relationship between 
degree-days and temperature. Monthly Weather Review 82 (9):1-6. 



heating 



18 



TABLE 2 



FREQUENCY CLASSES AND 30-YfcAR AVERAGES 
OF DEGREE-DAYS ABOVE 5°C FROM JANUARY 1 



CLASS FREQUENCY AND BOUNDARY 



SIDNEY. 6,C 



WEEK 
ENDING 



APR 



MAY 



JUNE 



JULY 



AUG 



SEP 



OCT 



1 

8 
15 
22 
29 

6 
13 
20 
27 

3 
10 
17 

2a 
i 

8 
15 
22 
29 

5 
12 
19 
26 

2 

9 
16 
23 
30 

7 
14 
21 
28 



RECORD 
LOW 
39 
55 
67 
80 
92 

122 

144 

184 

217 

252 

330 

381 

446 

495 

551 

628 

698 

762 

629 

904 

983 
1049 
1125 
1210 
1261 
1306 
1352 
1391 
1418 
1449 
1478 



MB 



59 

72 

92 

123 

141 

173 

222 

275 

319 

372 

448 

514 

577 

644 

718 

799 

873 

946 

1024 

1100 

1175 

1260 

1334 

1396 

1461 

1516 

1565 

1616 

1664 

1688 

1710 



NORMAL 
87 



MA 



105 
136 

160 
187 
226 
280 
325 
372 
427 
489 
550 
614 
676 
758 
836 
924 

1012 
1089 

1174 
1247 
1331 
1398 
1473 
1530 
1592 
1642 
169B 
1736 
1762 
1789 



107 

129 

149 

175 

209 

250 

296 

347 

407 

470 

534 

599 

664 

744 

822 

895 

972 

1056 

1136 

1216 

1287 

1368 

1446 

1518 

1582 

1649 

1721 

1759 

1805 

1833 

1862 



160 

18? 

204 

228 

268 

302 

354 

408 

47() 

528 

587 

667 

737 

805 

886 

974 

1062 

1147 

1239 

1326 

1401 

1485 

1559 

1630 

169ft 

1766 

1817 

1872 

1922 

1965 

1991 



RECORD 


DAIL 


HIGH 


MEAl 


224 


105 


254 


125 


284 


150 


321 


177 


375 


206 


416 


245 


471 


286 


510 


336 


577 


392 


63 


450 


696 


515 


779 


580 


878 


649 


948 


719 


1050 


796 


1145 


877 


1240 


961 


1356 


1043 


1449 


1123 


1543 


1206 


1636 


1287 


1735 


1364 


1805 


1437 


1885 


1509 


1961 


1574 


2012 


1632 


2064 


1687 


2118 


1734 


2159 


1775 


2197 


1806 


2224 


1835 



19 



TABLE 3 



FREQUENCY CLASSES AND 

OF OEGRtF-DAYS AHOVE 1 0°C 



30-YEAR AVERAGES 
FROM JANUARY 1 



SIDNEY B.C. 









CLASS 


E R E CO 1 1 E N C Y 


AND BOUNDARY 






WEEK 




RECORD 










RECORD 


DAILY 


ENDING 


LOW M 8 


H 


NORMAL 




A 


MA HIGH 


MEAN 


APW , 


1 





1 


2 


6 


14 


29 


6 




8 


1 


2 


a 


9 


17 


33 


9 




15 


3 


4 


10 


16 


24 


38 


13 




22 


3 


6 


13 


19 


32 


49 


18 




29 


a 


10 


20 


27 


39 


70 


25 


MAY 


6 


1 


16 


2^ 


37 


5* 


81 


35 




13 


12 


26 


43 


54 


73 


106 


49 




2 


22 


41 


56 


HO 


93 


114 


68 




27 


30 


62 


76 


103 


129 


153 


92 


JUNE 


3 


37 


81 


101 


122 


165 


190 


117 




10 


81 


108 


132 


153 


197 


240 


148 




17 


1 


136 


157 


160 


234 


288 


179 




24 


130 


164 


2 


225 


268 


352 


213 


JULY 


1 


145 


196 


233 


2 6 


306 


388 


248 




8 


167 


234 


266 


3 06 


350 


455 


291 




IS 


209 


28 


314 


356 


398 


514 


337 




22 


244 


320 


362 


403 


453 


575 


385 




29 


273 


363 


414 


450 


494 


656 


432 


AUG. 


5 


30b 


402 


464 


466 


546 


714 


478 




12 


346 


452 


505 


533 


597 


773 


526 




19 


390 


492 


545 


576 


653 


830 


572 




2h 


421 


541 


589 


624 


705 


895 


614 


SEP. 


2 


463 


574 


h?9 


66} 


7as 


929 


652 




9 


509 


605 


667 


7 04 


779 


975 


689 




16 


530 


632 


692 


729 


611 


10 15 


720 




23 


544 


656 


710 


759 


839 


1035 


745 




5 


558 


671 


738 


788 


661 


1055 


767 


OCT. 


7 


568 


688 


750 


796 


882 


1075 


783 




14 


572 


699 


761 


802 


89* 


1086 


794 




2\ 


577 


708 


765 


806 


909 


1093 


800 




28 


561 


715 


769 


813 


91U 


1096 


805 



20 



TABLE 4 




FREQUENCY 


CLASSES AND 


30- 


YEAR AVERAGES 










OF DEGREE 


DAYS ABOVE 13^C PROM JANUARY 


1 


















SIDNEY, B.C. 








CLASS FREQUENCY 


AND BOUNDARY 






WEEK 




RECORD 


i 








RECORD 


DAILY 


ENDING 


LOW 


MB 


H NORMAL 




A MA 


HIGH 


MEAN 


APR. 


1 














2 


6 


1 




8 











1 


3 


6 


1 




15 








1 


2 


5 


8 


2 




22 








1 


3 


9 


10 


3 




29 








2 


5 


12 


18 


5 


MAY 


6 


1 


1 


5 


9 


17 


20 


8 




13 


t 


3 


10 


17 


23 


32 


13 




20 


3 


7 


1ft 


26 


35 


aa 


21 




27 


5 


13 


23 


32 


5a 


71 


31 


JUNE 


3 


5 


2a 


32 


a3 


67 


88 


a2 




10 


22 


35 


uS 


62 


8a 


117 


57 




17 


3 a 


a6 


56 


78 


99 


146 


72 




2a 


a7 


56 


7a 


95 


117 


189 


89 


JULY 


1 


5a 


72 


98 


111 


139 


206 


107 




a 


61 


89 


119 


139 


162 


252 


131 




is 


83 


112 


iai 


165 


199 


290 


157 




22 


100 


133 


173 


197 


23a 


331 


186 




29 


ui 


160 


198 


226 


259 


391 


214 


AUG, 


s 


126 


182 


229 


2a8 


293 


a28 


2ao 




12 


ia8 


209 


253 


279 


330 


a67 


268 




19 


172 


230 


278 


302 


368 


5oa 


29a 




26 


185 


259 


300 


326 


396 


5a7 


316 


SEP. 


2 


205 


273 


311 


3aa 


ai? 


563 


336 




9 


216 


291 


331 


360 


a33 


590 


356 




16 


226 


299 


3a9 


369 


aai 


611 


370 




23 


236 


306 


360 


381 


a52 


617 


380 




30 


2a3 


312 


367 


391 


a58 


62a 


389 


OCT. 


7 


244 


321 


3 7a 


399 


a6i 


631 


39a 




ia 


2a5 


32a 


375 


399 


a67 


632 


396 




21 


2a7 


325 


376 


399 


a69 


633 


397 




28 


2a7 


327 


376 


aoo 


a69 


633 


398 



21 



TABLE 5 




FREQUENCY 


CLASSES AND 


n 30-YEAR AVERAGES 










OF DEGREE 


DAYS ABOVE 


5°C 


FROM JANUARY 


1 


















SUMMERLANDj B.C. 








CLASS FREQUENCY 


AND BOUNDARY 






WEEK 




RECORC 


) 








RECORD 


DAILY 


ENDING 


10* 


MB 


B NORMAL 


A MA 


HIGH 


MEAN 


APR, 


1 


15 


32 


43 


56 


86 


119 


54 




8 


39 


49 


66 


81 


112 


150 


79 




15 


63 


79 


101 


112 


137 


195 


109 




22 


61 


113 


132 


149 


171 


243 


143 




29 


92 


134 


171 


186 


206 


312 


178 


MAY 


6 


130 


177 


211 


235 


260 


365 


223 




13 


162 


228 


261 


29b 


323 


424 


279 




20 


215 


283 


317 


363 


395 


483 


344 




27 


256 


345 


396 


438 


484 


563 


416 


JUNE 


3 


304 


423 


472 


506 


559 


633 


493 




10 


394 


491 


557 


584 


672 


709 


577 




17 


489 


590 


643 


675 


778 


809 


663 




24 


581 


686 


726 


7b5 


867 


952 


757 


JULY 


1 


644 


784 


817 


851 


950 


1046 


846 




8 


720 


874 


926 


966 


1055 


1165 


951 




IS 


847 


983 


1045 


1087 


1169 


1286 


1066 




22 


969 


1099 


1147 


1193 


1294 


1437 


1180 




29 


1066 


1211 


1265 


1316 


1400 


1574 


1295 


AUG. 


5 


1159 


1 325 


1377 


1432 


1510 


1694 


1408 




12 


1273 


1422 


1489 


1546 


1628 


1826 


1521 




19 


1383 


1512 


1585 


1664 


1735 


1958 


1627 




26 


1472 


1597 


1689 


1770 


1829 


2103 


1726 


SEP. 


2 


1572 


1680 


17 89 


1660 


1925 


2196 


1816 




9 


1648 


1749 


1879 


1940 


2020 


2290 


1901 




16 


1718 


1822 


1965 


2010 


2099 


2372 


1977 




23 


1787 


1885 


2020 


2079 


2186 


2424 


2042 




30 


1848 


1928 


2081 


2147 


2237 


2469 


2102 


OCT. 


7 


1869 


1962 


2118 


2205 


2281 


2533 


2148 




14 


19J1 


1988 


2155 


2237 


2318 


2560 


2186 




21 


1949 


2014 


2165 


2262 


2347 


2590 


2214 




28 


1957 


2033 


2186 


2291 


2367 


2603 


2232 



22 



TABLE 6 



FREQUENCY 
OF DEGREE 



CLASSES 4NH 
DAYS A B U V E 



1 C 



30-YEAR AVERAGES 
FROM JANUARY 1 

SUMMERLAND 



d,C, 



CLASS FREQUENCY AND BOUNDARY 



WEEK 




RECORD 




ENDING 


L » MB 


APR. 


1 





2 




e 


2 


5 




15 


8 


12 




21 


9 


18 




29 


12 


27 


MAY 


6 


30 


39 




13 


a2 


5a 




2 


6a 


87 




27 


76 


119 


JU^E 


3 


97 


165 




10 


153 


201 




17 


214 


250 




24 


272 


305 


JULY 


l 


302 


361 




B 


344 


a22 




15 


a 36 


a<?b 




22 


519 


569 




29 


579 


657 


AUG. 


5 


643 


721 




12 


715 


788 




19 


776 


8a7 




26 


817 


917 


SEP. 


2 


871 


957 




9 


912 


1004 




16 


947 


10 36 




23 


982 


106a 




30 


1012 


1082 


OCT. 


7 


1017 


109? 




14 


1036 


10 96 




21 


104 7 


1 102 




26 


10a7 


1 10b 



NORMAL 

a 



MA 



8 
18 

2a 

38 
54 
79 
107 
142 
188 
23 7 
26a 
33a 
407 

462 
55a 

63 
7 09 
761 
8S7 
921 
986 
1 05a 
1 103 

1147 
1 176 
1205 
1225 
1243 
12aa 
12a8 



7 

15 

25 

ao 

51 

76 

102 

140 

171 

210 

267 

329 

383 

438 

512 

587 

670 

752 

«35 

912 

1001 

1068 

1127 

1166 

1208 

12a8 

1281 

1297 

1313 

1318 

1319 



15 
23 

38 

52 

68 
88 
130 
165 
229 
270 
33a 
378 
433 

a82 

558 

65 4 

7a7 

816 

902 

984 

1056 

1126 

1198 

1246 

1268 

1291 

1321 

1345 

1364 

1377 

1383 



RECORD 


DAILY 


HIGH 


MEAN 


26 


7 


45 


14 


51 


23 


73 


35 


110 


47 


132 


66 


161 


92 


194 


125 


246 


165 


294 


209 


361 


258 


435 


310 


535 


369 


593 


424 


676 


495 


764 


574 


88 


653 


981 


733 


1067 


812 


1 163 


889 


1261 


960 


1371 


1025 


1428 


1080 


1488 


1131 


1536 


1173 


1555 


1205 


1572 


1234 


1603 


1252 


1609 


1265 


1616 


1271 


1617 


1275 



23 



TABLE 


: 7 




FREQUENCY 


CLASSES AND 


30-YEAR AVERAGES 










OF- DEGREE 


DAYS ABOVE 13^C EROM 


JANUARY 


1 


















SUMMERLANO, B t C, 








CLASS FREQUENCY 


AND BOUNDARY 






WEEK 




RECORC 


i 








RECORD 


DAILY 


ENDING 


LQi* 


M8 


B NORMAL 


A 


MA 


HIGH 


MEAN 


APR. 


l 











1 


3 


8 


2 




8 








1 


4 


9 


18 


4 




15 


1 


2 


4 


7 


14 


18 


7 




22 


1 


4 


7 


15 


23 


27 


12 




29 


1 


7 


13 


19 


30 


49 


17 


MAY 


6 


9 


1 1 


19 


31 


40 


57 


27 




13 


13 


16 


34 


47 


67 


80 


41 




20 


23 


35 


46 


68 


85 


112 


59 




27 


28 


51 


66 


86 


115 


153 


83 


June 


3 


38 


78 


98 


115 


155 


182 


110 




10 


75 


101 


123 


151 


196 


229 


141 




17 


111 


124 


151 


190 


215 


285 


175 




2a 


152 


161 


189 


225 


267 


361 


215 


JULY 


1 


170 


196 


233 


260 


293 


399 


251 




8 


19a 


235 


287 


318 


350 


462 


301 




15 


263 


29 


349 


372 


431 


527 


361 




22 


31 1 


338 


396 


430 


499 


623 


419 




29 


352 


406 


452 


487 


561 


703 


479 


AUG. 


5 


a oo 


446 


513 


550 


612 


7 68 


536 




12 


448 


493 


570 


613 


681 


843 


593 




19 


488 


532 


609 


676 


736 


919 


644 




26 


510 


581 


648 


726 


790 


1008 


688 


SEP. 


2 


545 


612 


69U 


767 


837 


1045 


725 




9 


568 


649 


718 


79a 


852 


1087 


758 




16 


585 


671 


747 


824 


862 


1114 


783 




23 


604 


687 


762 


842 


674 


1121 


800 




30 


619 


698 


778 


854 


890 


1128 


815 


OCT. 


7 


621 


700 


786 


864 


901 


1144 


823 




14 


629 


701 


788 


867 


909 


1145 


827 




21 


631 


703 


788 


871 


914 


1146 


829 




28 


631 


7 04 


789 


871 


914 


1147 


830 



24 



TABLE 8 



FREQUENCY 
OF DEGREE 



CLASSES AND 
HAYS AMOVE 



5°C 



30„YEAH AVERAGES 
FROM JANUARY 1 

LETHBRIDGEj ALTA, 



CLASS FREQUENCY AND BOUNDARY 



WEEK 




RECORD 




ENDING 


LOW 


MB 


APR. 


i 


10 


17 




8 


11 


31 




15 


17 


40 




22 


no 


53 




29 


au 


65 


MAY 


6 


^3 


90 




13 


52 


116 




20 


107 


157 




27 


160 


202 


JUNE 


3 


204 


252 




10 


256 


299 




17 


329 


369 




24 


390 


434 


JULY 


1 


480 


49a 




8 


54b 


577 




15 


643 


683 




22 


746 


773 




2<? 


844 


872 


AUG. 


5 


930 


960 




12 


1024 


1041 




19 


1 104 


1123 




26 


llo3 


1195 


SEP. 


2 


1 189 


1282 




9 


1251 


1352 




16 


1302 


1397 




23 


1336 


1432 




30 


1353 


1455 


OCT. 


7 


1393 


1491 




i a 


1439 


1520 




21 


1439 


1543 




?8 


14/4 4 


1566 



NORMA 
28 



MA 



4 

58 

76 

96 

120 

157 

203 

255 

311 

375 

445 

512 

588 

681 

77a 

857 

947 

104b 

1127 

1207 

1287 

1343 

1402 

1458 

1506 

1569 

1614 

1653 

167 6 

1691 



47 

6u 

HO 

110 

131 

169 

203 

249 

298 

357 

4 27 

4 89 

574 

639 

720 

819 

917 

1013 

1 103 

1.20 

1285 

1349 

1424 

1480 

1533 

1583 

1644 

1676 

1702 

1722 

1733 



68 
8 4 
109 
140 
161 
187 
243 
29? 

342 
4 08 
469 
537 
609 
683 
769 

852 
947 
1054 
1 15? 
1240 
1336 
1428 
1495 
1568 
1626 
167 4 
171? 
1765 
1789 
1824 
1850 



RECORD 


DAILY 


HIGH 


MEAN 


91 


40 


96 


54 


124 


73 


157 


93 


203 


115 


232 


144 


272 


179 


311 


224 


360 


276 


416 


333 


500 


395 


564 


461 


666 


532 


757 


603 


862 


691 


961 


784 


1063 


880 


1146 


974 


1256 


1068 


1347 


1158 


1446 


1243 


1555 


1323 


1636 


1391 


169 


1453 


1727 


1507 


1750 


1551 


1771 


1594 


1622 


1631 


18 8 


1663 


1923 


1689 


1946 


1709 



25 



TABLE 9 



FREQUENCY 
OF DEGREE 



CLASSES AND 
DAYS A V E 



io°c 



30-YEAR AVERAGES 
FROM JANUARY 1 



CLASS FREQUENCY AND BOUNDARY 



LETHRRIDGE ALTA, 



WEEK 




RECORD 


ENDING 


LO* 


APR, 


1 







8 







15 


1 




22 


4 




29 


4 


MAY 


6 


5 




13 


6 




20 


33 




27 


ua 


JUNE 


3 


61 




10 


8b 




17 


116 




2^ 


163 


JULY 


1 


197 




8 


237 




IS 


2RS 




22 


357 




29 


413 


AUG. 


5 


4feb 




ia 


525 




19 


575 




26 


604 


SEP. 


2 


606 




Q 


637 




16 


658 




23 


674 




3 


6 8 


OCT. 


7 


6R2 




14 


712 




21 


712 




28 


713 



MB 



1 
3 

5 

Q 

14 

21 
31 

47 
67 
87 
109 
139 
178 
210 
256 
323 
384 
44 3 
495 
549 
590 
634 
677 
711 
736 
747 
761 
77 7 
795 
803 
816 



NORMAL 
3 



MA 



9 

14 

16 

24 

32 

40 

74 

94 

120 

148 

183 

222 

256 

318 

371 

430 

483 

542 

596 

652 

690 

725 

750 

781 

792 

818 

833 

856 

872 

878 



9 
12 
23 

30 
41 
54 
69 
81 
115 
144 
177 
217 
258 
292 
340 
401 
465 
522 
575 
639 
684 
730 
769 
800 
834 
860 
878 
88 7 
90 1 
908 
909 



13 

20 

30 

41 

58 

70 

92 

110 

140 

173 

210 

248 

294 

321 

372 

426 

503 

576 

643 

701 

761 

808 

832 

87 5 

908 

935 

965 

990 

1014 

1027 

1028 



RECORD 


DAILY 


HIGH 


MEAN 


21 


7 


27 


11 


33 


17 


53 


24 


72 


33 


81 


44 


112 


59 


138 


79 


160 


104 


187 


132 


239 


163 


278 


197 


345 


235 


402 


273 


472 


327 


536 


386 


603 


447 


652 


506 


727 


566 


784 


622 


848 


673 


922 


719 


969 


756 


994 


789 


1010 


816 


1018 


836 


10 39 


857 


1064 


873 


1065 


886 


1079 


896 


1080 


903 



26 



TABLE 10 FREQUENCY CLASSES AND 30„YEAR AVERAGES 

OF DEGREE DAYS ABOVE 13 C FROM JANUARY 1 



LETHBRIDGE 



WEEK 




RECORD 


ENDING 


LOW 


APR, 


1 







8 







15 







IZ 







29 





MAY 


6 







13 







20 


15 




27 


17 


JUNE 


3 


2a 




10 


37 




17 


50 




2a 


76 


JULY 


1 


95 




8 


118 




15 


159 




12 


201 




2<? 


241 


AUG, 


5 


276 




12 


316 




19 


3a 




26 


35a 


SEP. 


2 


361 




9 


379 




16 


388 




23 


397 




30 


aoo 


OCT. 


7 


ao3 




14 


ai5 




21 


ai5 




28 


ai5 



CLASS FREQUENCY AND BOUNDARY 



MB B NORMAL A MA 

2 a 

3 a 6 

1 5 8 12 

2 5 11 18 
a 9 16 28 
6 ia 22 3a 

io 19 32 aa 

18 32 at 52 

31 aa 56 70 

a3 57 73 96 

51 72 89 126 

69 93 111 142 

86 110 135 167 

107 136 162 180 

136 176 190 215 

18a 2ia 235 252 

223 250 275 317 

257 291 316 36? 

296 328 361 ao? 

329 365 394 449 

352 a05 a24 487 

382 429 450 519 

400 454 478 536 

414 468 497 564 

437 477 518 587 

442 493 533 599 

456 505 5ao 609 

46a 515 546 626 

480 522 553 635 

485 524 553 644 

491 528 555 647 



RECORD 


DAILY 


HIGH 


MEAN 


10 


2 


11 


3 


13 


6 


26 


9 


35 


14 


38 


19 


62 


27 


77 


37 


90 


51 


107 


66 


136 


8a 


173 


loa 


220 


127 


259 


ia9 


310 


185 


354 


225 


401 


267 


432 


308 


486 


3ae 


526 


386 


570 


a20 


624 


aa9 


654 


a72 


667 


a92 


676 


508 


681 


519 


695 


531 


712 


539 


712 


5a6 


719 


550 


719 


554 



27 



TABLE 11 



FREQUENCY 
OF DEGREE 



CLASSES AND 
DAYS ABOVE 



5°C 



30-YEAR AVERAGES 
FROM JANUARY 1 

BEAVERLODGE. ALTA, 



CLASS FREQUENCY AND BOUNDARY 



tfEEK 




RECORD 




iNDING 


LOw 


MB 


APR, 


1 





1 




8 





2 




15 


1 


5 




22 


1 


12 




29 


a 


16 


MAY 


6 


17 


37 




13 


25 


55 




20 


67 


91 




27 


106 


133 


JUNE 


3 


164 


177 




10 


210 


230 




17 


256 


286 




2a 


312 


335 


JULY 


l 


380 


396 




8 


446 


463 




15 


517 


545 




I?. 


579 


612 




29 


640 


677 


AUG. 


5 


711 


739 




12 


770 


804 




19 


817 


866 




26 


880 


914 


SEP. 


2 


927 


972 




9 


946 


1003 




16 


973 


1048 




23 


996 


1080 




30 


1011 


1104 


OCT. 


7 


1043 


1117 




14 


1059 


1131 




21 


1066 


1147 




2R 


1077 


1155 



NORMAL 

5 



MA 



7 

14 

19 

35 

54 

83 

1 13 

158 

203 

253 

317 

376 

434 

500 

574 

646 

720 

BOfe 

872 
934 
985 
1043 
1084 
1131 
1 159 
1188 
1207 
1218 
1228 
1249 



8 

14 

19 

31 

43 

64 

105 

142 

192 

252 

310 

351 

416 

482 

556 

620 

690 

761 

838 

925 

994 

1067 

1114 

1165 

1204 

1259 

1283 

1303 

1332 

1342 

1343 



16 

32 

49 

74 

97 

139 

177 

227 

285 

356 

424 

496 

557 

632 

711 

805 

877 

965 

1044 

1119 

1191 

1245 

1293 

1337 

1361 

1378 

1401 

1410 

1433 

143* 



RECORD 


DAILY 


HIGH 


MEAN 


18 


7 


40 


12 


59 


20 


85 


30 


137 


45 


173 


66 


195 


95 


228 


134 


275 


179 


333 


229 


402 


286 


458 


344 


527 


404 


610 


465 


698 


537 


789 


613 


906 


691 


986 


762 


1044 


838 


1124 


911 


1204 


976 


1279 


1037 


1308 


1088 


1348 


1133 


1402 


1175 


1428 


1208 


1452 


1237 


1486 


1260 


1535 


1279 


1566 


1293 


1590 


1301 



28 



TABLE 12 FREQUENCY CLASSES And 30 -YEAH AVERAGES 

OF DEGREE DAYS ABOVE 10 C FRO* JANUARY 1 



BEAVERLODGE 



WEEK 




RECORD 


ENDING 


LOw 


APR. 


1 







8 







IS 







22 







29 





MAY 


6 


2 




13 


3 




20 


16 




27 


27 


JUNE 


3 


39 




10 


50 




17 


66 




24 


93 


JULY 


1 


126 




8 


173 




IS 


210 




22 


24 1 




29 


270 


AUG. 


5 


306 




12 


335 




19 


352 




2b 


385 


SEP. 


2 


395 




9 


399 




16 


408 




23 


413 




30 


414 


OCT . 


7 


427 




14 


440 




21 


440 




28 


44 2 



CLASS FREQUENCY AND BOUNDARY 



MR B NOKMAL A MA 

1 

14 

2 6 

2 5 9 

1 5 7 17 
4 8 15 25 
9 17 30 42 

2 35 4 7 64 

35 51 70 90 

58 67 89 12a 

79 93 t)6 156 

10 1 12b 141 181 

123 150 168 219 

155 175 201 265 

191 209 241 31? 

230 247 285 357 

264 293 324 417 

292 326 361 458 

327 379 414 511 

357 405 458 552 

385 4U3 494 601 

406 461 534 619 

435 489 556 636 

458 509 587 672 

472 527 615 682 

483 532 634 690 

487 546 648 715 

492 564 654 721 

49a 567 656 724 

496 569 657 728 

497 572 657 72* 



RECORD 


DARY 


HIGH 


MEAN 


2 





9 


1 


13 


3 


20 


5 


45 


9 


57 


16 


63 


26 


83 


42 


103 


62 


137 


84 


186 


112 


228 


140 


269 


168 


306 


198 


333 


237 


387 


279 


460 


323 


506 


361 


531 


404 


575 


443 


622 


477 


676 


507 


697 


530 


704 


550 


726 


568 


728 


580 


731 


591 


744 


599 


757 


604 


769 


607 


776 


609 



29 



TABLE 


13 




FREQUENCY 


CLASSES AND 


rs 30 


-YEAR AVERAGES 










OF DEGREE 


HAYS ABOVE 13~C 


FROM 


JANUARY 1 




















BEAVERLOOGE, 


ALTA, 








CLASS FREQUENCY 


AND BOUNDARY 






WEEK 




RECORC 












RECORD 


DAILY 


ENDING 


LOw 


MB 


B NORMAL 




A 




MA HIGH 


MEAN 


APR. 


1 


l) 
























8 
















1 


3 







15 
















2 


4 


1 




22 











1 




4 


7 


1 




29 








1 


2 




5 


20 


3 


MAY 


6 





1 


2 


6 




10 


25 


6 




13 





2 


5 


13 




21 


27 


10 




20 


u 


6 


14 


22 




29 


38 


18 




27 


7 


13 


22 


32 




47 


56 


29 


JUNE 


3 


11 


22 


29 


44 




63 


85 


«i 




10 


15 


34 


44 


59 




83 


117 


55 




17 


21 


4 4 


59 


72 




98 


142 


70 




24 


33 


54 


72 


90 




115 


164 


86 


JULY 


1 


SO 


73 


85 


104 




14fe 


164 


102 




8 


8 


90 


104 


129 




1 77 


197 


125 




15 


102 


112 


125 


154 




206 


236 


150 




22 


120 


129 


149 


179 




246 


275 


178 




29 


1.35 


148 


170 


20 3 




268 


302 


200 


AUG, 


5 


147 


170 


211 


233 




302 


329 


226 




12 


165 


179 


223 


262 




329 


356 


249 




19 


174 


191 


246 


287 




361 


387 


268 




26 


183 


206 


253 


309 




370 


424 


285 


SEP. 


2 


185 


214 


263 


322 




375 


434 


297 




9 


187 


224 


278 


343 




393 


435 


307 




16 


191 


234 


285 


356 




398 


447 


316 




23 


191 


242 


288 


361 




407 


447 


322 




3 


191 


247 


288 


368 




418 


448 


328 


OCT. 


7 


198 


248 


299 


370 




420 


453 


330 




14 


204 


249 


303 


371 




425 


461 


333 




21 


20 6 


250 


304 


374 




427 


464 


334 




2* 


207 


250 


304 


374 




427 


464 


334 



30 



TABLE 14 



FREQUENCY 
OF DEGREE 



CLASSES AND 
DAYS ABOVE 



b°C 



30. year AVERAGES 
FROM JANUARY 1 
SWIFT 



CLASS FREQUENCY AND BOUNDARY 



CURRENT, SASK, 



WEEK 




RECORD 




ENDING 


LOW 


MB 


APR. 


1 





1 




8 





3 




15 


3 


8 




22 


7 


17 




29 


14 


38 


MAY 


6 


22 


55 




13 


32 


82 




20 


78 


126 




27 


148 


166 


JUNE 


3 


196 


222 




10 


239 


271 




17 


302 


340 




2a 


367 


408 


JULY 


l 


432 


484 




8 


532 


565 




15 


6 30 


658 




22 


737 


757 




29 


826 


863 


AUG, 


5 


903 


968 




12 


987 


1051 




19 


1052 


1145 




26 


1104 


1244 


SEP. 


2 


1185 


1316 




9 


1262 


1383 




16 


1278 


1420 




23 


1344 


1430 




30 


1366 


1445 


OCT. 


7 


1391 


1490 




14 


1421 


1518 




21 


1427 


1540 




2« 


1443 


1566 



NORMAL 

a 



MA 



11 

25 

44 

62 

90 

129 

175 

225 

288 

350 

429 

488 

565 

658 

759 

840 

934 

1038 

1 142 

1216 

1287 

1373 

1440 

1492 

1538 

1574 

1619 

166 

168b 

1897 



11 

30 

45 

65 

85 

116 

156 

20b 

271 

322 

402 

467 

536 

615 

704 

801 

901 

994 

1099 

1201 

1293 

1380 

1458 

1520 

15b2 

1610 

1657 

1689 

1699 

1725 

1735 



30 

40 

62 

93 

123 

153 

192 

245 

295 

360 

431 

507 

576 

b72 

776 

87? 

96« 

1062 

1175 

125b 

1354 

1436 

1531 

1612 
168"* 
1741 
1779 
1814 
184 4 
1658 
1868 



RECORD 

HIGH 
40 
45 
77 

112 

162 

204 

281 

332 

375 

446 

547 

6 06 

679 

749 

842 

942 
1042 
1150 
1263 
1374 
1473 
1582 
1668 
1727 
1766 
1797 
1823 
1880 
1942 
1992 
2021 



DAILY 
MEAN 
12 
20 
36 
55 
78 

107 

142 

186 

240 

300 

366 

437 

508 

585 

677 

775 

874 

972 
1073 
1167 
1258 
1342 
1413 
1476 
1530 
1572 
1610 
1642 
1672 
1694 
1708 



31 



TABLE 15 



FREQUENCY 
OF DEGREE 



CLASSES am 
hAYS ABlJVfc 



10 c 



30.yeAR AVERAGES 
FRQM JANUARY 1 

s*ift current, sask, 



CLASS FREQUENCY AND BOUNDARY 



WEEK 




RECORD 


ENDING 


L i*l 


APR. 


1 







8 







15 







22 


1 




29 


2 


MAY 


6 


2 




1 3 


5 




20 


26 




27 


49 


JUNE 


3 


62 




10 


75 




17 


105 




24 


lao 


JULY 


1 


17a 




8 


239 




15 


302 




22 


376 




29 


a30 


AUG. 


5 


a72 




12 


522 




19 


5b2 




26 


59b 


SEP. 


2 


baa 




9 


667 




16 


681 




23 


700 




30 


713 


ocr. 


7 


719 




la 


726 




21 


7a7 




28 


747 



MB 







1 

3 
b 
13 
21 
38 
59 

8a 

103 

1 ab 

181 
223 
277 
329 
392 
459 
517 
562 
613 
676 
705 
736 
766 
783 
80 1 
822 
825 
627 
837 



NORMAL 




MA 



2 

5 

10 

16 

27 

42 

59 

83 

113 

152 

194 

22^ 

260 

317 

375 

42tf 

498 

572 

b30 

685 

725 

771 

808 

826 

64b 

673 

689 

91 1 

919 

92a 



2 
a 

11 

15 

25 

a2 

55 

75 

112 

147 

181 

220 

261 

297 

361 

a25 

a89 

560 
629 
695 
755 
795 
841 
882 
912 
918 
93b 
94b 
9b0 
9bb 
9b7 



b 

9 

15 

31 

49 

61 

83 

107 

136 

173 

221 

253 

30b 

353 

a29 

a9o 

5a5 

602 
671 
725 

788 

8a5 

913 

950 

997 

1022 

1047 

1058 

1062 

1067 

1070 



RECORD 


DAILY 


HIGH 


MEAN 


10 


2 


12 


a 


27 


9 


a3 


16 


69 


25 


87 


37 


133 


52 


162 


72 


183 


99 


222 


130 


288 


166 


316 


20a 


357 


2a3 


a22 


287 


5 7 


3aa 


573 


408 


b33 


a72 


b9a 


536 


782 


602 


845 


662 


922 


719 


100b 


770 


10 59 


809 


1090 


8a3 


1107 


870 


11 19 


889 


112a 


906 


l laa 


920 


1155 


932 


1 173 


941 


1173 


945 



32 



TABLE 16 



FREQUENCY 
OF DEGREE 



CLASSES AND 
DAYS ABOVE 



13°C 



30-YEAR AVERAGES 
FROM JANUARY 1 
S*IFT 



CURRENT, 



CLASS FREQUENCY AND BOUNDARY 



WEEK 




RECURD 


ENDING 


LOW 


APR, 


1 







8 







lb 







22 







2* 





MAY 


6 







13 


1 




20 


12 




27 


20 


JUNE 


3 


21 




10 


12 




17 


47 




2 a 


69 


JULY 


1 


87 




M 


134 




15 


178 




22 


217 




29 


256 


AUG. 


5 


290 




12 


321 




19 


344 




2b 


363 


SEP. 


2 


394 




9 


4 05 




16 


411 




21 


421 




30 


428 


OCT. 


7 


432 




14 


436 




21 


446 




28 


4 46 



MB 







1 
1 

4 

8 

17 

28 

41 

51 

74 

96 

117 

154 

195 

236 

279 

312 

350 

3B2 

411 

426 

444 

461 

467 

488 

494 

499 

502 

S06 



N () R M \ L, 




MA 





2 

3 

6 

10 

18 

28 

39 

59 

76 

107 

119 

141 

181 

219 

268 

318 

364 

400 

435 

477 

498 

50 7 

527 

533 

549 

558 

563 

568 

571 





1 

4 

5 

11 

19 

28 

37 

57 

84 

101 

123 

146 

175 

215 

256 

308 

360 

404 

458 

500 

527 

551 

576 

595 

598 

610 

617 

624 

627 

627 



2 
3 

6 
15 

24 
31 
46 
60 
79 
102 
134 
158 
187 
214 
271 
314 
350 
391 
44-5 
484 
521 
566 
60 7 
628 
657 
676 
690 
69a 
695 
697 
700 



ECORD 


DAILY 


HIGH 


MEAN 


5 


1 


5 


1 


13 


3 


22 


6 


40 


It 


48 


17 


76 


25 


95 


36 


107 


52 


130 


71 


177 


92 


199 


115 


236 


139 


285 


166 


350 


205 


396 


249 


438 


294 


480 


339 


547 


386 


592 


428 


649 


466 


712 


501 


750 


525 


768 


546 


777 


562 


783 


572 


785 


582 


797 


589 


803 


596 


814 


599 


814 


602 



33 



TABLE 17 FREQUENCY CLASSES AND Q 30-yfeAR AVERAGES 

OF DEGREE. DAYS ABOVE 5 C FROM JANUARY 1 



CLASS FREQUENCY AND BOUNDARY 



NORMAL A MA 

1 19 

1 6 2a 
9 17 43 

25 35 73 

33 70 105 

75 107 155 

97 141 199 

149 186 255 

20 2 4 B 311 

25« 316 382 

335 396 447 

421 470 521 

505 545 609 

596 643 711 

677 747 825 

784 848 928 

895 963 1040 

996 1074 1165 

1099 U70 1269 

1191 1270 1375 

1277 1366 1487 

1380 1467 1575 

1469 1535 1671 

1540 1611 1732 

15H6 1679 1796 

1636 1729 1631 

1664 1757 1903 

1699 1788 1934 

1751 1796 19S3 

1781 1827 1969 

1782 1839 1977 



WINNIPEG, MAN, 



WEEK 




RECORO 




ENDING 


LOW 


MB 


APR. 


1 










8 










15 





1 




22 


2 


5 




29 


4 


23 


MAY 


6 


7 


37 




13 


29 


49 




20 


60 


80 




27 


119 


135 


JUNE 


3 


159 


180 




10 


225 


246 




17 


288 


327 




24 


391 


412 


JULY 


1 


464 


496 




8 


542 


589 




15 


619 


700 




22 


730 


809 




29 


840 


911 


AUG. 


5 


939 


1004 




12 


1032 


1089 




19 


1108 


1175 




26 


1163 


1264 


SEP. 


2 


1256 


1350 




9 


1328 


1424 




16 


1382 


1461 




23 


1436 


1496 




30 


1476 


1533 


OCT. 


7 


1507 


1546 




14 


1521 


1576 




21 


1550 


1589 




28 


1567 


1596 



RECORO 


DAILY 


HIGH 


MEAN 


33 


5 


42 


8 


83 


20 


102 


35 


171 


58 


251 


91 


283 


125 


320 


168 


392 


224 


431 


287 


524 


361 


624 


441 


709 


524 


796 


617 


902 


715 


993 


818 


1133 


925 


1237 


1031 


1363 


1136 


1470 


1237 


1597 


1330 


1705 


1424 


1810 


1507 


1884 


1577 


1943 


1634 


1991 


1681 


2016 


1718 


2048 


1753 


2095 


1782 


2153 


1807 


2198 


1818 



34 



TABLE 18 




FREQUENCY 


CLASSES AND 


30-YEAR AVERAGES 










OF DEGREE 


DAYS A b U V E 


]0°C 


FROM JANUARY 


1 


















4 I N N I P E Gj MAN, 








CLASS FREQUENCY 


AND BOUNDARY 










RECORO 










RECORD 


DAILY 






10* 


MR 


h NORMAL 


A MA 


HIGH 


MEAN 


APR. 


1 














2 


8 


1 




8 














6 


8 


1 




15 








1 


a 


12 


25 


5 




22 








5 


9 


2a 


ai 


10 




29 





a 


9 


26 


36 


97 


20 


MAY 


6 





7 


2a 


38 


71 


145 


36 




13 


b 


11 


32 


59 


91 


157 


50 




20 


15 


19 


55 


71 


Ha 


170 


70 




27 


42 


51 


82 


1 11 


ia8 


211 


98 


JUNE 


3 


51 


73 


113 


156 


191 


226 


132 




10 


*2 


108 


154 


193 


226 


285 


173 




17 


113 


ia8 


220 


238 


280 


350 


220 




2a 


162 


20 a 


258 


28a 


331 


401 


270 


JULY 


1 


221 


247 


314 


3a 7 


a oq 


a52 


329 




8 


262 


310 


37 a 


ai3 


a69 


52a 


392 




15 


309 


384 


435 


a89 


5a7 


574 


461 




22 


39a 


451 


510 


560 


628 


67 o 


533 




29 


466 


500 


571 


630 


709 


739 


604 


AUG. 


5 


533 


5S8 


6a7 


708 


781 


630 


674 




12 


569 


621 


720 


777 


861 


90 3 


740 




19 


61 


683 


776 


828 


939 


995 


799 




26 


645 


747 


633 


890 


1 1 


1068 


859 


SER. 


2 


686 


798 


688 


927 


1046 


1138 


9 09 




9 


702 


836 


906 


98a 


1080 


1179 


947 




16 


767 


849 


923 


1010 


1105 


1209 


975 




23 


797 


856 


950 


1022 


1123 


1228 


995 




30 


81 3 


871 


968 


1031 


1 162 


1235 


1011 


OCT. 


7 


816 


875 


978 


ioa9 


1 191 


1244 


1026 




ia 


82a 


882 


99a 


1055 


1197 


1278 


1037 




21 


825 


89a 


1013 


1076 


1201 


1311 


1046 




28 


825 


89S 


1013 


1076 


1207 


1332 


1049 



35 



TABLE 19 



FREQUENCY CLASSES AND Q 30-yEAR AVERAGES 
OF OEGREF DAYS ABOVE 13 C FRqm JANUARY 1 



CLASS FREQUENCY AND BOUNDARY 



WINNIPEG MAN, 



APR 



MAY 



JUNE 



JULY 



AUG 



SEP 



OCT 





RECORD 




LOW 


1 





8 





IS 





22 





29 





6 





13 


2 


20 


5 


27 


19 


3 


21 


10 


38 


17 


55 


2a 


100 


1 


114 


8 


135 


15 


183 


21 


238 


29 


278 


5 


328 


12 


355 


19 


363 


26 


3 8 


2 


405 


9 


410 


16 


455 


23 


469 


30 


478 


7 


4 79 


14 


4*3 


21 


483 


28 


483 



MB 









1 

2 

4 

7 

25 

38 

57 

82 

119 

141 

1 84 

231 

273 

309 

355 

397 

450 

491 

516 

532 

540 

54U 

551 

552 

560 

56? 

563 



NORMAL 




MA 







1 

3 

9 

14 

27 

42 

61 

84 

124 

146 

186 

22 

269 
322 
375 

420 
468 
510 
554 
582 
594 
6 05 
618 
629 
637 
643 
6 4 9 
649 







1 

4 

12 

19 

28 

38 

59 

89 

114 

145 

172 

212 

268 

320 

372 

423 

481 

514 

547 

602 

632 

664 

674 

688 

689 

699 

705 

709 

709 





2 

5 

9 

18 

41 

52 

65 

85 

113 

139 

168 

213 

256 

316 

366 

418 

484 

541 

603 

657 

696 

725 

746 

760 

768 

785 

800 

801 

8 02 

803 



RECORD 


DAILY 


HIGH 


MEAN 


3 





3 





12 


2 


25 


4 


66 


9 


99 


19 


104 


26 


no 


37 


136 


54 


143 


7a 


183 


100 


227 


130 


259 


162 


290 


202 


341 


246 


390 


294^ 


452 


346 


506 


397 


571 


447 


627 


493 


694 


534 


747 


575 


797 


607 


823 


630 


840 


646 


851 


656 


853 


665 


855 


672 


872 


678 


889 


683 


9 01 


684 



36 



TABLE 20 



FREQUENCY 
OF DEGREE 



CLASSES AND 
DAYS ABOVE 



5°C 



30-Yfc'AR AVERAGES 
FROM JANUARY 1 



CLASS FREQUENCY AND BOUNDARY 



HARROW ONT 



APR 



MAY 



JUNE 



JULY 



AUG 



SEP 



OCT 





RECORD 






L0*i 


MB 


! 


a 


12 


8 


12 


26 


15 


25 


43 


22 


49 


63 


29 


81 


107 


6 


105 


155 


13 


163 


204 


20 


205 


265 


27 


273 


335 


3 


342 


408 


to 


427 


516 


17 


553 


593 


2a 


637 


689 


i 


754 


812 


8 


854 


918 


15 


969 


1036 


22 


1098 


1156 


29 


1229 


1276 


5 


1342 


1393 


12 


1459 


1507 


19 


1565 


1629 


26 


1656 


1737 


2 


1758 


1.837 


9 


1857 


1944 


16 


19^1 


2040 


23 


2008 


2110 


30 


2067 


2168 


7 


2128 


2218 


14 


2180 


2268 


21 


2252 


2304 


28 


2295 


2326 



NORMAL 
28 



MA 



39 

58 

90 

137 

185 

242 

315 

385 

472 

569 

675 

781 

892 

994 

1 106 

1225 

1355 

1477 

1593 

1711 

1826 

1932 

2031 

2124 

2224 

2287 

2340 

2381 

2422 

2476 



43 

61 

82 

125 

161 

220 

275 

333 

421 

508 

609 

714 

834 

958 

1072 

1189 

1323 

1450 

1573 

1684 

1794 

1912 

2044 

2169 

2252 

2319 

2404 

2482 

2534 

2564 

2593 



66 

8a 

127 

181 

232 

3oa 

355 

429 

50U 

595 

690 

79? 

91? 

1045 

1165 

1291 

1421 

155a 

169? 

181? 

19U 

2023 

2136 

2250 

2359 

2456 

2514 

2593 

2678 

2723 
2768 



RECORD 


DAILY 


HIGH 


MEAN 


157 


41 


199 


59 


272 


83 


311 


118 


333 


160 


358 


215 


399 


268 


4U7 


336 


536 


410 


619 


49a 


736 


591 


836 


695 


942 


804 


1088 


927 


1239 


1043 


1353 


1161 


1488 


1283 


1639 


1409 


1753 


1529 


1895 


1646 


2014 


1761 


2120 


1870 


2226 


1985 


2313 


2090 


24 7 


2181 


2512 


2268 


2586 


2337 


2673 


2404 


2717 


2461 


27b3 


2511 


2799 


2547 



37 



TABLE 21 



FREQUENCY 
OF DEGREE 



CLASSES and 
HAYS ABOVE 



10°c 



30 -YEAR AVERAGES 
FROM JANUARY 1 



CLASS FREQUENCY AND BOUNDARY 



NARROW. OnT, 



APR 



MAY 



JUNE 



JULY 



AUG 



SEP 



OCT 





RECORD 






LO* MR 


1 








6 


2 


a 


15 


a 


8 


22 


11 


13 


?9 


19 


22 


6 


2a 


48 


13 


<42 


67 


20 


72 


91 


27 


105 


133 


3 


la8 


166 


10 


198 


242 


17 


276 


294 


24 


325 


365 


1 


tt07 


451 


8 


472 


532 


15 


552 


610 


22 


641 


682 


29 


726 


767 


5 


79b 


841 


1? 


683 


924 


19 


948 


1012 


26 


1 o a 


1084 


2 


1072 


1152 


9 


1136 


1221 


16 


1187 


1271 


23 


1230 


1312 


30 


1277 


1345 


7 


1290 


1381 


14 


1 323 


1 397 


21 


1351 


1409 


26 


1362 


14 16 



N P M A L 
5 



MA 



8 
13 
26 

4H 

b5 
101 
135 
161 

213 
28 u 
356 
431 
5<>6 
578 
659 
73a 
827 
901 
99 3 
10 54 
1144 

1205 
1273 
1329 

14 7 
14 49 
1479 
1510 
1529 
1539 



8 

1 * 

24 

^2 

68 

69 

125 

151 

205 

253 

315 

373 

455 

551 

628 

712 

819 

905 
983 
1055 
1 128 
1228 
1310 

1393 

1459 
1501 
1547 
1577 
1616 
1629 
1638 



16 

28 

4S 

67 

90 

131 

155 

206 

259 

306 

368 

451 

54(b 

640 

7 30 

815 

907 

10 13 

10 94 

1179 

1267 

13U3 

1424 

1465 

1565 

1618 

1653 

1696 

1730 

1744 

17 75 



RECUR D 


DAILY 


HIGH 


MEAN 


7 2 


10 


89 


15 


132 


24 


145 


39 


150 


57 


161 


65 


189 


HO 


239 


146 


289 


188 


354 


238 


4 30 


301 


4 99 


370 


579 


444 


666 


532 


784 


613 


863 


697 


963 


784 


1079 


875 


1158 


959 


1266 


1042 


1349 


1122 


1421 


1196 


1497 


1276 


1567 


1346 


1629 


1404 


1700 


1457 


1743 


1495 


1796 


1531 


1611 


1559 


1829 


1582 


1846 


1596 



38 



TABLE 22 



FREQUENCY CLASSES AND 



o. 



30 .YEAR AVERAGES 



OF DEGREE DAYS ABOVE 15 C FRO* JANUARY 1 



HARROW, ONT, 



CLASS FREQUENCY AND BOUNDARY 



APR 



MAY 



JU^E 



JULY 



AUb 



SEP 



OCT 





RECORD 










RECORD 


DAILY 




LOW MR 




d NORMAL 




A 


MA HIGH 


MEAN 


1 








1 


2 


8 


38 


4 


8 





1 


2 


5 


10 


4b 


6 


is 


1 


2 


4 


10 


21 


73 


10 


?.? 


2 


a 


10 


20 


28 


79 


17 


29 


3 


8 


20 


30 


45 


80 


27 


6 


9 


2o 


31 


45 


79 


105 


43 


13 


15 


31 


4b 


bO 


90 


121 


58 


20 


33 


43 


71 


80 


119 


165 


79 


27 


54 


bb 


8 3 


108 


152 


19b 


105 


3 


77 


84 


117 


143 


194 


241 


137 


10 


lib 


133 


158 


188 


235 


297 


181 


17 


161 


170 


210 


237 


300 


345 


230 


24 


186 


220 


ibi 


29b 


373 


404 


285 


1 


242 


288 


330 


3b4 


451 


47b 


352 


8 


299 


334 


387 


422 


513 


570 


412 


15 


364 


395 


442 


482 


57b 


b28 


475 


22 


413 


453 


498 


5b2 


b44 


708 


541 


29 


•477 


51b 


570 


b25 


726 


8 02 


611 


5 


52b 


582 


b3b 


b90 


794 


860 


675 


12 


592 


b44 


b9b 


738 


855 


947 


73b 


1^ 


b37 


704 


741 


807 


921 


1013 


796 


2b 


b73 


749 


791 


871 


977 


10b4 


850 


2 


721 


808 


855 


931 


1035 


1128 


909 


9 


7b5 


841 


895 


987 


1082 


1180 


960 


lb 


799 


87b 


949 


1033 


1143 


1221 


999 


23 


823 


902 


992 


1063 


1 172 


1273 


1035 


30 


852 


920 


1013 


1095 


1199 


1301 


1057 


7 


858 


944 


1029 


1111 


1221 


1335 


10 79 


la 


877 


950 


1034 


1140 


1237 


1342 


1095 


21 


892 


958 


1056 


1 145 


1253 


1351 


1107 


2a 


89b 


9b4 


1060 


1150 


1274 


1359 


1113 



39 



TABLE 2 3 



FREQUENCY 
OF OEGRFF- 



CLASSES AND 
DAYS ABOVE 



s°c 



30. YEAR AVERAGES 
FROM JANUARY 1 



CLASS FREQUENCY AND BOUNDARY 



OTTAWA, ONT , 



APR 



MAY 



JUNE 



JULY 



AUG 



SEP 



OCT 





RECORD 






LOw 


MB 


1 








8 





2 


15 


1 


9 


22 


5 


19 


29 


29 


34 


6 


45 


74 


13 


76 


99 


20 


HI 


146 


27 


145 


214 


3 


224 


291 


10 


294 


364 


17 


377 


447 


24 


472 


529 


1 


566 


627 


8 


68} 


708 


15 


784 


818 


21 


874 


935 


29 


969 


1056 


5 


1055 


1 162 


12 


1171 


1272 


19 


1275 


1374 


2b 


1345 


1476 


2 


1426 


1555 


9 


1505 


1627 


16 


1563 


1685 


23 


1590 


1751 


30 


1624 


1792 


7 


1663 


1844 


14 


1693 


1885 


21 


1740 


1905 


26 


1765 


191? 



NORMAL 
1 



MA 



6 

14 

36 

66 

111 

147 

210 

274 

335 

420 

496 

593 

701 

804 

919 

1013 

1121 

1227 

1324 

1426 

1516 

1607 

1708 

1784 

1843 

1882 

1925 

19h0 

19«9 

20 13 



6 

10 

30 

54 

81 

128 

178 

235 

302 

374 

453 

552 

649 

761 

861 

976 

1092 

1201 

1300 

1405 

1496 

1584 

1685 

1774 

1850 

1916 

1967 

1999 

2036 

2070 

2089 



19 

38 

54 

84 

12? 

172 

216 

276 

350 

428 

512 

603 

691 

798 

908 

1013 

1137 

1264 

1374 

1503 

1589 

1700 

1800 

1871 

1943 

2006 

2047 

2095 

2156 

2195 

2206 



RECORD 


DAILY 


HIGH 


MEAN 


56 


9 


73 


14 


131 


29 


147 


51 


162 


78 


185 


119 


237 


162 


296 


217 


377 


281 


444 


352 


537 


433 


635 


523 


741 


618 


652 


727 


982 


827 


1106 


937 


1242 


1047 


1358 


1161 


1502 


1266 


1615 


1371 


1750 


1471 


1866 


1565 


1962 


1658 


2036 


1743 


2096 


1813 


2172 


1876 


2225 


1924 


2268 


1968 


2330 


2006 


2353 


2038 


2365 


2057 



40 



TABLE 2 4 



FREUUfcNCY CLASSES AND 



o. 



30-YfcAR AVERAGES 



OF UfrGREE DAYS ABOVE 10 C FRO* JANUARY 1 



CLASS FREQUENCY AMU BOUNDARY 



Ottawa M T 



APR 



MAY 



JUNE 



JULY 



AUG 



SEP 



OCT 





RECORD 










RECORD 


DAILY 




LOw MB 


B NORMAL 


A 


MA HIGH 


MEAN 


1 














3 


19 


2 


8 











1 


g 


24 


3 


15 








2 


4 


17 


56 


7 


22 





2 


7 


13 


28 


60 


14 


29 


2 


7 


16 


23 


54 


61 


24 


6 


a 


16 


33 


48 


66 


92 


41 


13 


19 


29 


47 


71 


97 


111 


60 


20 


32 


48 


75 


98 


123 


145 


86 


27 


45 


7b 


102 


133 


169 


186 


120 


3 


85 


118 


141 


171 


212 


235 


159 


10 


119 


154 


178 


223 


270 


283 


206 


17 


168 


210 


239 


283 


327 


348 


262 


24 


217 


257 


306 


342 


385 


417 


322 


1 


280 


320 


379 


407 


461 


494 


396 


8 


339 


375 


44 3 


475 


536 


588 


461 


15 


414 


457 


524 


559 


606 


677 


536 


22 


467 


530 


587 


633 


69 


776 


611 


2<? 


552 


606 


666 


7 08 


789 


859 


690 


5 


608 


675 


729 


777 


867 


968 


760 


12 


689 


754 


7MB 


845 


948 


1046 


831 


19 


746 


806 


864 


909 


1014 


1146 


895 


26 


794 


8bS 


932 


960 


1090 


1227 


955 


2 


841 


914 


983 


1024 


1149 


1289 


1014 


9 


888 


951 


10 37 


1075 


1188 


1331 


1065 


16 


918 


98 3 


1080 


1 114 


1227 


1361 


1104 


23 


923 


1031 


1119 


1157 


1258 


1407 


1137 


30 


934 


1054 


1131 


1181 


1272 


1431 


1158 


7 


947 


1081 


114 4 


1207 


1.291 


1447 


1176 


14 


956 


1096 


1 lbl 


1213 


1323 


1476 


1191 


21 


979 


no? 


1 lb9 


1218 


1335 


1478 


1203 


28 


98 7 


1 102 


1178 


1221 


1343 


1481 


1208 



41 



TABLE 2 5 




FREQUENCY 


CLASSES AND 





0-YEAR AVERAGES 










OF DEGREE 


DAYS ABOVE 13~C 


FROM 


JAMUARY 


1 




















OTTAWA, ONT, 








CLASS FREQUENCY 


AND BOUNDARY 










RECORC 












RECORD 


DAILY 






LOW 


MB 


6 NORMAL 




A 


MA 


HIGH 


MEAN 


APR, 


1 
















1 


9 


1 




6 
















3 


10 


1 




15 











1 




8 


31 


3 




22 








2 


5 




13 


32 


6 




29 





1 


5 


10 




29 


32 


IS 


MAY 


6 


1 


5 


13 


^ 




3a 


55 


20 




13 


5 


11 


20 


37 




50 


61 


30 




20 


16 


19 


33 


51 




69 


8a 


a3 




27 


22 


31 


51 


72 




95 


107 


63 


JUNE 


3 


3a 


60 


70 


9 3 




125 


ia9 


86 




10 


5a 


75 


102 


128 




165 


179 


116 




17 


82 


112 


137 


162 




199 


219 


153 




2a 


108 


139 


179 


213 




2a6 


268 


19a 


JULY 


l 


151 


19a 


232 


261 




307 


32a 


2a7 




8 


190 


227 


277 


305 




366 


398 


293 




15 


2aa 


283 


331 


359 




ai5 


a67 


3a7 




22 


279 


332 


386 


a21 




a75 


5a7 


ao2 




29 


3a2 


390 


a37 


a75 




5a6 


607 


a60 


AUG. 


5 


392 


a37 


a82 


523 




611 


695 


510 




12 


aa6 


a92 


523 


563 




660 


753 


560 




19 


a78 


528 


573 


609 




7)5 


832 


605 




26 


508 


569 


615 


6aa 




771 


893 


6a6 


SEP. 


2 


5a3 


597 


6fc2 


69a 




6ia 


936 


686 




9 


567 


617 


691 


725 




839 


962 


719 




16 


59 


638 


723 


7a5 




862 


979 


7a2 




23 


59a 


668 


7a3 


769 




877 


1011 


762 




30 


598 


680 


751 


781 




883 


1021 


772 


OCT, 


7 


603 


698 


758 


792 




891 


1028 


782 




la 


609 


70a 


759 


79a 




908 


ioa3 


789 




21 


619 


707 


768 


802 




918 


loa3 


79a 




28 


622 


707 


77a 


802 




921 


loaa 


796 



42 



TABLE 2 6 



FREQUENCY 
OF DEGREE 



CLASSES AND 
DAYS ABOVE 



5°C 



30»YEAR AVERAGES 
FROM JANUARY 1 

FREDERICTQN 



CLASS FREQUENCY AND BOUNDARY 



N,B, 



APR. 



MAY 



JUNE 



JULY 



AUG 



SEP 



OCT 





RECORD 






LOW 


MB 


1 


1 


2 


8 


2 


a 


15 


4 


8 


22 


9 


14 


29 


17 


27 


6 


32 


41 


13 


48 


70 


20 


67 


1 12 


27 


86 


168 


3 


130 


221 


10 


222 


282 


17 


288 


341 


24 


359 


425 


1 


467 


509 


8 


561 


593 


IS 


655 


693 


22 


743 


803 


29 


834 


90 6 


5 


911 


1005 


12 


1009 


1100 


19 


1098 


1184 


26 


1159 


1269 


2 


1229 


1347 


9 


1307 


1422 


16 


1362 


1467 


23 


1389 


1519 


30 


1411 


1557 


7 


1438 


1593 


14 


1455 


1620 


21 


1497 


1667 


28 


1520 


1678 



NORMAL 

5 



MA 



6 

12 

28 

42 

70 

98 

141 

193 

250 

308 

381 

464 

561 

642 

740 

845 

941 

1043 

1130 

1228 

1315 

1385 

1458 

1513 

1582 

1634 

1664 

1689 

1724 

1737 



8 

12 

19 

36 

59 

82 

122 

165 

222 

276 

339 

415 

492 

591 

678 

771 

871 

980 

1082 

1174 

1255 

1340 

1429 

1513 

1583 

1640 

1695 

1734 

1774 

1793 

1806 



16 

28 

37 

51 

68 

106 

141 

187 

24a 

312 

373 

461 

533 

628 

727 

833 

937 

1035 

1133 

1259 

1348 

1432 
15 32 
1609 
1669 
1720 
1769 
1801 
1853 
1869 
1880 



RECORD 


DAILY 


HIGH 


MEAN 


32 


8 


43 


13 


88 


21 


102 


34 


117 


51 


134 


75 


175 


109 


213 


150 


282 


203 


339 


262 


418 


324 


521 


398 


604 


479 


698 


571 


798 


661 


886 


761 


976 


861 


1075 


962 


1177 


1060 


1287 


1 156 


1392 


1251 


1467 


1334 


1570 


1418 


1639 


1492 


1704 


1554 


1773 


1610 


1824 


1656 


1881 


1693 


1904 


1.726 


1912 


1753 


1925 


1770 



43 



TABLE 2 7 




FREQUENCY 


CLASSES AND 


10°C ~ 


JO-YEAR AVERAGES 










OF DEGREE 


DAYS A 8 o V t 


FROM JANUARY 


1 


















FREDERICTQN, N t b„ 








CLASS FREQUENCY 


AMD BOUNDARY 










RECORD 










RECORD 


DAILY 






LOw 


MR 


8 NORMAL 


A M/i 


HIGH 


MEAN 


APR, 


1 














1 


7 


1 




8 











1 


4 


10 


1 




15 











2 


6 


34 


3 




22 





1 


2 


6 


12 


36 


6 




29 


I 


2 


8 


10 


17 


39 


10 


MAY 


6 


a 


6 


1? 


21 


32 


49 


19 




13 


7 


14 


23 


35 


54 


62 


31 




2 


1 1 


27 


39 


54 


67 


87 


48 




27 


IS 


52 


69 


81 


99 


126 


73 


JUNE 


3 


3a 


75 


91 


104 


137 


164 


102 




to 


77 


103 


120 


136 


177 


206 


134 




17 


107 


13^ 


156 


180 


228 


267 


175 




2a 


1«S 


181 


211 


233 


266 


316 


223 


JULY 


1 


218 


233 


271 


288 


321 


375 


279 




e 


271 


287 


31 9 


346 


390 


440 


335 




15 


33b 


364 


3«3 


411 


458 


49U 


400 




?Z 


38 


4?5 


452 


U68 


525 


549 


465 




29 


425 


486 


517 


542 


586 


625 


532 


AUG. 


5 


477 


549 


576 


604 


664 


692 


595 




12 


524 


599 


648 


664 


7 22 


767 


656 




19 


577 


647 


699 


726 


796 


839 


716 




26 


619 


693 


750 


774 


851 


887 


766 


SEP. 


2 


671 


744 


794 


830 


9 08 


946 


815 




9 


714 


779 


828 


877 


947 


984 


856 




16 


742 


798 


85b 


923 


986 


1029 


888 




23 


7 48 


817 


899 


947 


1007 


1065 


915 




30 


756 


837 


918 


970 


1028 


1077 


935 


OCT. 


7 


76 


84 7 


926 


985 


1040 


1106 


949 




10 


763 


865 


932 


100 1 


1 066 


till 


960 




21 


78 1 


879 


950 


10 11 


1076 


till 


969 




28 


788 


88 


952 


1014 


1078 


1114 


973 



44 



TABLE 2 8 




FREQUENCY 


CLASSES AND 


30-YEAR AVERAGES 










OF DEGREE 


(JAYS ABOVE 13~C 


FROM JANUARY 


1 


















FREDERICTON, n.B, 








CLASS FREQUENCY 


AND BOUNDARY 










RECORD 










RECORD 


DAILY 






LUw 


MR 


8 NORMAL 




A MA 


HIGH 


MEAN 


APR. 


t 

















2 







8 














1 


4 







15 














2 


18 


1 




22 











1 


5 


19 


2 




29 








2 


3 


7 


19 


4 


MAY 


b 





1 


3 


8 


16 


26 


7 




13 


1 


4 


8 


14 


28 


31 


13 




20 


2 


10 


17 


26 


33 


46 


21 




27 


3 


22 


29 


41 


55 


67 


36 


JUNE 


3 


14 


31 


43 


55 


77 


94 


52 




10 


31 


48 


60 


74 


103 


120 


70 




17 


as 


72 


82 


103 


135 


158 


95 




2a 


72 


94 


117 


131 


158 


189 


126 


JULY 


1 


104 


133 


156 


168 


196 


229 


163 




8 


135 


164 


185 


208 


245 


273 


200 




15 


187 


213 


233 


252 


292 


309 


245 




22 


220 


253 


282 


295 


335 


352 


290 




29 


2<J7 


292 


325 


351 


377 


416 


337 


AUG, 


5 


279 


335 


368 


389 


427 


464 


380 




12 


306 


364 


M8 


432 


470 


518 


422 




19 


340 


394 


448 


478 


530 


572 


462 




26 


364 


421 


48 


504 


568 


602 


493 


SEP. 


2 


40 7 


453 


506 


542 


595 


641 


525 




9 


424 


471 


521 


578 


619 


664 


549 




16 


437 


480 


537 


597 


639 


686 


567 




23 


4ao 


487 


564 


616 


661 


707 


582 




30 


443 


50 


567 


627 


668 


714 


591 


OCT. 


7 


450 


502 


574 


635 


674 


729 


598 




i« 


450 


508 


579 


639 


686 


730 


602 




21 


453 


514 


584 


640 


687 


730 


606 




28 


453 


514 


584 


642 


689 


731 


607 



45 



TABLE 2 9 




FRE.QUE.NiCY 


CLASSES AND 


30. YEAR AVERAGES 










OF DEGREE 


DAYS ABOVE 


5 C 


FROM JANUARY 


1 


















KENTVILLE^ N,S, 








CLASS FREQUENCY 


AND BOUNDARY 










RECORC 










RECORD 


DAILY 






LOW 


MB 


B NORMAL 


A MA 


HIGH 


MEAN 


APR, 


1 


1 


3 


10 


16 


31 


51 


16 




8 


1 


6 


16 


22 


42 


76 


23 




15 


3 


11 


2? 


33 


53 


95 


31 




22 


10 


18 


38 


53 


69 


111 


45 




29 


16 


25 


51 


69 


95 


121 


61 


MAY 


6 


28 


50 


74 


92 


126 


149 


85 




13 


51 


71 


108 


128 


168 


206 


118 




20 


77 


104 


143 


172 


210 


242 


157 




27 


96 


168 


197 


223 


266 


281 


210 


JUNE 


3 


135 


235 


259 


262 


31? 


350 


266 




10 


225 


2«3 


317 


338 


370 


429 


327 




17 


301 


344 


388 


409 


444 


500 


398 




2a 


382 


409 


467 


480 


539 


586 


477 


JULY 


l 


471 


501 


559 


583 


b?h 


697 


567 




6 


555 


578 


647 


673 


721 


79 


658 




15 


666 


686 


750 


7 74 


814 


891 


759 




2? 


750 


779 


652 


874 


9?fe 


991 


860 




29 


8 US 


883 


951 


978 


1033 


1091 


962 


AUG. 


5 


9ia 


986 


1052 


1081 


1129 


1203 


1062 




12 


1006 


1074 


1 151 


1187 


1234 


1295 


1160 




19 


1098 


116J 


12^0 


1286 


1347 


1402 


1257 




26 


1170 


1248 


1324 


136 


144 


1501 


1343 


SEP. 


2 


1244 


1332 


1404 


1467 


1520 


1605 


1428 




9 


1325 


1399 


1475 


1540 


1600 


1687 


1504 




16 


1389 


1461 


1540 


1614 


1676 


1769 


1574 




23 


1429 


1515 


1610 


1673 


1762 


1824 


1635 




30 


1454 


1563 


1656 


1739 


1801 


1882 


1689 


OCT. 


7 


1492 


1611 


1694 


1781 


1841 


1915 


1732 




14 


1519 


1640 


1737 


1811 


1695 


1936 


1772 




21 


1554 


1681 


1776 


1854 


1933 


1968 


1805 




28 


1580 


1697 


1805 


1670 


196? 


1984 


1829 



46 



TABLE 30 




FREQUENCY 


CLASSES AND 


30-YEAR AVERAGES 










OF DEGREE 


DAYS ABOVE 1 


IOC 


FROM JANUARY 


1 


















KENTVILLE ; N,S t 








CLASS FREQUENCY 


AND BOUNDARY 










RECORC 










RECORD 


DARY 






LOW 


MR 


R NORMAL 


A ma 


MIGM 


MEAN 


APW. 


1 











2 


5 


8 


2 




ft 








1 


2 


7 


15 


3 




15 








2 


5 


8 


35 


5 




22 





1 


4 


9 


15 


39 


9 




29 


1 


3 


9 


15 


1ft 


40 


12 


MAY 


6 


3 


6 


16 


20 


37 


47 


20 




13 


7 


13 


25 


34 


54 


7? 


32 




20 


12 


21 


43 


52 


70 


92 


47 




21 


16 


45 


68 


7« 


91 


116 


71 


JUNE 


3 


32 


74 


9 


104 


123 


157 


97 




10 


67 


104 


117 


135 


155 


203 


128 




17 


113 


134 


154 


169 


20 


241 


167 




?4 


156 


179 


199 


212 


257 


294 


212 


JULY 


l 


200 


232 


?49 


277 


306 


3 7 


268 




8 


2<J5 


280 


310 


337 


363 


426 


324 




15 


322 


345 


376 


401 


430 


494 


390 




22 


371 


396 


446 


470 


509 


559 


457 




29 


a25 


458 


514 


536 


580 


624 


524 


AUG. 


5 


488 


526 


5 70 


602 


66 


700 


589 




\2 


545 


574 


637 


678 


732 


762 


653 




19 


604 


624 


665 


744 


81? 


830 


715 




26 


643 


675 


735 


787 


«66 


694 


767 


SEP. 


2 


683 


728 


762 


645 


911 


963 


818 




9 


732 


764 


618 


693 


961 


1011 


661 




16 


766 


795 


863 


937 


too? 


1059 


899 




23 


779 


816 


902 


965 


1 4 3 


1083 


930 




30 


785 


84? 


931 


99? 


10 7? 


1110 


955 


OCT . 


7 


796 


856 


947 


10 9 


1085 


1118 


972 




1*1 


806 


861 


96 


1031 


mo 


1 121 


968 




21 


819 


879 


973 


1033 


1119 


1147 


1000 




2ft 


829 


88} 


981 


1035 


1125 


1 156 


10 07 



47 



TABLE 31 



FREQUENCY 
OF DEGREE 



CLASSES AND 
DAYS ABOVE 



U°C 



30. YEAR AVERAGES 
FRO* JANUARY 1 



CLASS FREQUENCY AND BOUNDARY 



KENTVILLE. M,S, 



APR 



MAY 



JUNE 



JULY 



AUG 



SEP. 



OCT 





RECORD 




LOw 


1 





8 





15 





22 





29 





6 





13 


1 


20 


2 


27 


3 


3 


11 


10 


4! 


17 


52 


?« 


7a 


1 


97 


8 


125 


15 


179 


22 


209 


2^ 


243 


5 


288 


12 


323 


19 


364 


26 


389 


2 


424 


9 


4S0 


16 


468 


23 


474 


3 


475 


7 


482 


14 


48 7 


21 


491 


28 


491 



MB 









1 

2 

5 

15 

30 

47 

64 

91 

123 

157 

203 

239 

28 

317 

346 

377 

406 

443 

463 

<J79 

487 

500 

505 

5 06 

515 

515 



NORMAL 





MA 






1 
3 

4 

8 

16 

29 

41 
56 
75 
104 
141 
178 
225 
268 
317 
359 

40 1 
428 
463 
497 
527 
544 
568 
583 
595 
596 
603 
605 







1 

2 

3 

7 

17 

23 

37 

50 

67 

92 

117 

161 

197 

244 

?9a 
337 

3B3 
437 
485 
510 
545 
576 
602 
625 
641 
655 
658 
659 
662 



1 

2 

? 

6 

8 

16 

24 

29 

46 

61 

81 

1 14 

146 

183 

226 

27? 

324 

374 

43? 

485 

543 

578 

615 
648 
673 
694 
710 
715 
720 
725 
726 



RECORD 


DAILY 


HIGH 


MEAN 


3 





6 


1 


17 


1 


19 


3 


19 


4 


24 


7 


39 


13 


47 


19 


60 


32 


85 


46 


114 


64 


137 


87 


170 


115 


225 


151 


263 


189 


308 


235 


353 


282 


399 


329 


458 


374 


520 


418 


561 


461 


600 


493 


636 


527 


667 


552 


714 


575 


725 


593 


726 


606 


739 


613 


746 


620 


765 


625 


770 


628 



48 



TABLE 3 2 



FREQUENCY CLASSES AND 
OF OEGRfcP DAYS ABOVE 



s°c 



30. Y FAW AVERAGES 
F R N JANUARY ! 

CMARLOTTtTOWNP t t.I f 



CLASS FREQUENCY AND BOUNDARY 



APR. 



MAY 



JUNE 



JULY 



AUG, 



SEP. 



OCT. 





RECORD 






LOW 


MB 


1 





1 


8 





1 


IS 


1 


2 


22 


2 


5 


29 


3 


11 


6 


8 


24 


13 


23 


38 


20 


41 


67 


27 


55 


105 


3 


79 


155 


10 


169 


214 


17 


228 


271 


2a 


301 


336 


1 


39 


415 


8 


453 


a 97 


15 


519 


599 


ZZ 


597 


704 


29 


678 


8 05 


5 


775 


9 05 


12 


66b 


992 


19 


956 


10 73 


?6 


10 29 


1 145 


2 


1128 


1223 


9 


1193 


1289 


16 


1260 


1353 


23 


1303 


1403 


30 


1347 


1448 


7 


1396 


1485 


14 


1419 


1506 


21 


14U8 


1542 


28 


1461 


1568 



NORMAL 
2 



MA 



3 

6 
11 

23 

34 
61 
8 9 
135 
188 
232 
288 
369 
4h3 
556 
h39 
742 
635 
9«3 

104b 
1 15(1 
1238 
1322 

1401 
1 463 

1525 
1569 
1612 
1650 
1692 
1702 



4 

7 

10 

21 

32 

5S 

81 

117 

162 

203 

256 

326 

401 

490 

562 

687 

792 

896 

10 05 

1105 

1215 

1.294 

1376 

1453 

1521 

1577 

1635 

1685 

1724 

1748 

1774 



12 

16 
27 

36 

62 

81 

1 14 

1 Uh 

195 

255 

303 
374 

aa7 

543 

635 

737 

632 

936 

1 4 4 

1155 

126? 

1 34 7 

1437 

1521 

1621 

1677 

1724 

1787 

1824 

1853 

1683 



RECORD 

HIGH 
18 
31 
56 
7 1 
75 
98 

126 

175 

242 

265 

355 

435 

516 

616 

7 29 

827 

922 
1021 
1116 
1214 
1329 
1429 
1539 
1621 
1 7 5 
1758 
18J9 
1861 
1902 
1917 
1965 



DAILY 

MEAN 

5 

8 

1? 

20 

31 

48 

73 

105 

150 

198 

252 

318 

394 

478 

568 

668 

769 

671 

971 

1071 

1 169 

1256 

1342 

1420 

1469 

1551 

1604 

1648 

1665 

1716 

1 737 



49 



TABLE 3 3 



FREQUENCY CLASSES AND 

OF DEGREE PAYS ABOVE 10° 



30„yEAH AVERAGES 

FROM JANUARY 1 

CHARLOTTETOwn .P.E.I, 



APR 



MAY 



J U n F 



JULY 



AUG 



SEP. 



OCT 







CLASS F 


REQUENCY 


AMD BOUNDARY 








RECORD 










RECORD 


DAILY 




LUw *8 


B 


M UP MAI 




A 


MA HIGH 


MEAN 


1 


n 











1 


2 





w 














2 


3 





15 














2 


17 


1 


22 











3 


6 


2 


3 


29 


n 





1 


5 


9 


21 


5 


h 





2 


5 


9 


20 


37 


10 


1 5 


2 


3 


13 


19 


33 


47 


17 


20 


U 


9 


22 


29 


4 3 


73 


27 


27 


6 


23 


41 


52 


68 


106 


46 


5 


lb 


3Q 


59 


70 


98 


124 


66 


1 


s? 


64 


76 


92 


127 


161 


89 


17 


to! 


9 3 


105 


122 


170 


204 


123 


24 


1 16 


127 


147 


175 


206 


251 


165 


1 


1 a 3 


1 74 


195 


22 


257 


315 


215 


M 


185 


22 


253 


281 


313 


393 


270 


lb 


216 


289 


320 


351 


377 


457 


335 


22 


26 


350 


390 


410 


448 


516 


400 


29 


4 6 


415 


45 


490 


525 


580 


407 


s 


368 


476 


514 


556 


606 


64 4 


533 


1? 


423 


518 


579 


619 


b77 


708 


598 


19 


'4 79 


58 


h34 


68a 


759 


788 


661 


26 


518 


625 


b96 


7 46 


81 


853 


713 


2 


5*2 


661 


7 46 


792 


M57 


928 


7ft4 


9 


61 3 


b99 


7 94 


636 


913 


9 75 


808 


16 


644 


722 


*20 


675 


970 


1024 


845 


23 


659 


754 


847 


9 02 


100 3 


10 4 4 


874 


30 


672 


768 


862 


951 


10 15 


1074 


898 


7 


691 


781 


672 


969 


10 39 


1085 


913 


1 a 


695 


789 


893 


976 


10 5 


10 96 


926 


21 


70 1 


8 05 


9 


967 


1068 


1098 


936 


26 


7 02 


816 


90 1 


995 


10 76 


1116 


941 



50 



TABLE 3 4 



FREQUENCY 
OF DEGRfcF 



CLASSES ANO 
DAYS ABOVE 



13°C 



30-YEAR AVERAGES 
FROM JANUARY 1 

CHARLOTTETOwN P,fc,I t 



CLASS FREQUENCY AND BOUNDARY 



APR. 



MAY 



JUNE 



JULY 



AUG 



SEP. 



OCT 





RECORD 




LOW 


I 





e 





is 





a 





29 





6 





13 





2o 





27 





3 


5 


10 


19 


17 


27 


24 


45 


1 


58 


8 


93 


lb 


106 


?? 


131 


29 


157 


5 


199 


1? 


233 


19 


269 


26 


290 


2 


333 


9 


348 


16 


36 


23 


365 


30 


36b 


7 


375 


14 


376 


21 


376 


28 


376 



MR 

















2 

8 

13 

23 

39 

61 

88 

112 

159 

20 

241 

285 

31 1 

353 

379 

397 

416 

426 

445 

454 

459 

461 

468 

470 



NORMAL 




MA 





o 





1 

2 

7 

16 

25 

34 

49 
73 
102 
138 
182 
230 
273 
315 
363 
403 
435 
466 
490 
506 
518 
521 
522 
531 
532 
533 








1 

2 

fe 

11 

20 

30 

42 

6 

90 

117 

157 

203 

248 

302 

34 6 

388 

433 

465 

500 

521 

553 

568 

596 

601 

603 

608 

610 







? 
? 

9 
14 
19 

32 

50 
66 
98 
120 
147 
186 
235 
265 
332 
39? 
441 
498 
541 
576 
599 

621 
656 

668 
676 
680 
680 
687 



RECORD 


DAILY 


HIGH 


MEAN 














8 





6 


1 


9 


1 


20 


3 


24 


6 


36 


10 


52 


19 


66 


29 


87 


41 


114 


59 


136 


84 


185 


115 


237 


150 


279 


195 


318 


240 


362 


286 


411 


331 


472 


375 


528 


418 


559 


451 


613 


483 


641 


508 


672 


528 


682 


544 


692 


555 


695 


561 


700 


566 


710 


569 


713 


571 



51 



2200 -: 



2000 



1800 



1600 -$ 



1 400 ~mm 



1200 



iooo -ivmm 



800 -g 



600 -m 



400 -S 



200 




5"C 



10"C 



13"C 



I I I I I 1 I I I I 

5 10 15 20 25 5 10 15 20 25 

APRIL MAY 



5 10 15 20 25 5 10 15 20 25 

OCT. NOV. 



Fig. 2. Average seasonal growing degree-day accumulations (5, 10, 13°C) and 
average freeze dates of a given severity at Charlottetown, P.E.I. 



52 



2200 



2000 



1800 



1600 



uj 1200 




1400 



1000 



5°C 



10"C v> 



m 



13°C 



10 15 20 25 

APRIL 



10 15 20 25 

MAY 



10 15 20 25 

JUNE 



5 10 15 20 25 

AUGUST 



Fig. 3. Average seasonal growing degree-day accumulations (5, 10, 13°C; 
average freeze dates of a given severity at Kentville, N.S. 



and 



53 



FREDERICTON 



2200 



2000 



1 800 -g 



1600 -| 




200 -B 



FREEZE-FREE PERIOD 
(130 days) 










111!! 

5 10 15 20 25 5 10 15 20 25 

OCT. NOV. 



5"C 



10"C 



13"C 



Fig. 4. Average seasonal growing degree-day accumulations (5, 10, 13°C) and 
average freeze dates of a given severity at Fredericton, N.B. 



54 



2200 -i 



2000 -s; 



1800 -& 



1600 *::■:/;. 



1400 - 



w 1200 -iSSiS 



1000 



800 I 



600 



400 - 



200 - 




I I T I I — I I I ! I 1 I I I I 1 I I I I 1 I I I I 1 I I I I 1 IT T — T 1 I I 1 

5 10 15 20 25 5 10 15 20 25 5 10 15 20 25 5 10 15 2025 5 10 15 20 25 5 10 15 2025 5 10 15 20 25 5 10 15 20; 

APRIL MAY JUNE JULY AUGUST SEPT. OCT. NOV. 



5°C 



10" C 



13°C 



Fig. 5. Average seasonal growing degree-day accumulations (5, 10, 13°C; 
average freeze dates of a given severity at Ottawa, Ont. 



and 



55 



2200 



2000 



1800 



1600 -I 



1400 - 



> 
< 
Q 

uj 1200 

c 

C3 



1000 -! 



800 -i 



600 -I 



400 ~\ 



200 -i 




5"C 



10"C 



13"C 



10 15 20 25 

APRIL 



Fig. 6. Average seasonal growing degree-day accumulations (5, 10, 13°C 
average freeze dates of a given severity at Harrow, Ont. 



and 



56 



2200 f . .. 




I I T ! I — TTT 

5 10 15 20 25 5 10 15 20 25 

APRIL MAY 



5"C 









i r 

5 10 15 20 25 

JUNE 



JULY 



AUGUST 



SEPT. 



T T T T 

5 10 1520 25 

NOV. 



Fig. 7. Average seasonal growing degree-day accumulations (5, 10, 13°C) and 
average freeze dates of a given severity at Winnipeg, Man. 



57 



SWIFT CURRENT 



2200 



2000 - 



1800 



1600 




1 400 - 



1200 



1000 - 



800 -te 



600 



400 -I 



200 



FREEZE-FREE PERIOD 
(109 days) 





5 10 15 20 25 

APRIL 



5 10 15 20 25 

OCT. 



I I I I 

5 10 1520 75 

NOV. 



5"C 



I0°C 



13°C 



Fig. 8. Average seasonal growing degree-day accumulations (5, 10, 13°C' 
average freeze dates of a given severity at Swift Current, Sask. 



and 



58 



LETHBRIDGE 



2200 -mmm 



2000 -w$M 






1600 






uj 1200 -m 



1000 -s 



800 -Wm 



600 -M 



400 -S 



200 -i 



FREEZE-FREE PERIOD 
(118 days) 




5"C 



10°C 



13°C 



JUNE 



JULY 



AUGUST 



SEPT 



VT 

5 10 15 20 25 

OCT. 



I I I I I 

5 10 15 20 26 

NOV. 



Fig. 9. Average seasonal growing degree-day accumulations (5, 10, 13°C; 
average freeze dates of a given severity at Lethbridge, Alta. 



and 



59 



BEAVERLODGE 



2200 - 



2000 - 



1800 - 



1600 - 



1400 



FREEZE-FREE PERIOD 
(108 days) 



















5°C 



5 10 15 20 25 

NOV. 



10 U C 



13°C 



Fig. 10. Average seasonal growing degree-day accumulations (5, 10, 1 3° C ] 
average freeze dates of a given severity at Beaverlodge, Alta. 



and 



60 



2200- 



2000 -j 



1800 



1600 -i 



1400-: 



w 1200 -\ 



1000- 



800- 



600 -I 



400 -i 



200 




5°C 



10°C 



13°C 



Fig. 1 1 . Average seasonal growing degree-day accumulations (5, 10, 13°C' 
average freeze dates of a given severity at Summerland, B.C. 



and 



61 



SIDNEY 



2200- 



2000- 



1800- 



1600- 



1400- 



f, 1200- 



1000- 



800- 



600- 



400- 



200- 




5°C 



10°C 



13°C 



5 1 1 5 20 25 

APRIL 



5 10 1520 25 



Fig. 12. Average seasonal growing degree-day accumulations (5, 10, 13°C) and 
average freeze dates of a given severity at Sidney, B.C. 



62 



CAUBCA OTTAWA K1 A 0C5 




^'9(1)73 00186833 2 



CONVERSION FACTORS FOR METRIC SYSTEM 




Approximate 






Imperial units conversion factor 


Results in: 


LINEAR 








inch 


x25 


millimetre 


(mm) 


foot 


x 30 


centimetre 


(cm) 


yard 


x 0.9 


metre 


(m) 


mile 


x 1.6 


kilometre 


(km) 


AREA 








square inch 


x6.5 


square centimetre 


(cm 2 ) 


square foot 


x 0.09 


square metre 


(m 2 ) 


acre 


x 0.40 


hectare 


(ha) 


VOLUME 








cubic inch 


x 16 


cubic centimetre 


(cm 3 ) 


cubic foot 


x 28 


cubic decimetre 


(dm 3 ) 


cubic yard 


x 0.8 


cubic metre 


(m 3 ) 


fluid ounce 


x28 


millilitre 


(mL) 


pint 


x 0.57 


litre 


(L) 


quart 


x 1.1 


litre 


(L) 


gallon 


x4.5 


litre 


(L) 


WEIGHT 








ounce 


x 28 


gram 


(g) 


pound 


x 0.45 


kilogram 


(kg) 


short ton (2000 lb) 


x 0.9 


tonne 


(t) 


TEMPERATURE 








degrees Fahrenheit 


(°F-32)x0.56 






or (°F-32) 


x 5/9 degrees Celsius 


(°C) 


PRESSURE 








pounds per square inch x 6.9 


kilopascal 


(kPa) 


POWER 








horsepower 


x 746 


watt 


(W) 




x 0.75 


kilowatt 


(kW) 


SPEED 








feet per second 


x 0.30 


metres per second 


(m/s) 


miles per hour 


x 1.6 


kilometres per hour 


(km/h) 


AGRICULTURE 








gallons per acre 


x 11.23 


litres per hectare 


(L/ha) 


quarts per acre 


x 2.8 


litres per hectare 


(L/ha) 


pints per acre 


x 1.4 


litres per hectare 


(L/ha) 


fluid ounces per acre 


x 70 


millilitres per hectare 


(mL/ha) 


tons per acre 


x 2.24 


tonnes per hectare 


(t/ha) 


pounds per acre 


x 1.12 


kilograms per hectare 


(kg/ha) 


ounces per acre 


x 70 


grams per hectare 


(g/ha) 


plants per acre 


x 2.47 


plants per hectare 


(plants/ha) 



63 



Canad'a