WHEAT IN CANADA 271 



Manitoba, Saskatchewan, and Alberta are the 

 great wheat provinces of the plains, and many 

 valleys in the mountainous province of British 

 Columbia are likewise well adapted to wheat 

 growing. The climate is the chief control. The 

 normal annual rainfall is about 22 inches in Man- 

 itoba, and from 16 to 18 inches in Saskatchewan 

 and Alberta. The rainfall, although not high, is 

 usually sufficient because the greater part of it, 

 50 to 65 per cent, occurs during the growing season. 

 June is the month of greatest rainfall. The sum- 

 mer temperatures are quite high, often reaching 

 90 F. ; and winter temperatures vary considerably 



in the different parts of the provinces. Southwest 

 Alberta has a milder winter than districts to the 

 east and north. This is due primarily to the 

 chinook winds, -- westerly winds, which upon 

 descending the mountains are warmed by com- 

 pression, and thus reach the plains quite dry and 

 warm. The average winter temperatures in dif- 

 ferent localities from December to March are : 

 Calgary i7.iF., Fort Chipewyan (northeast Al- 

 berta) 5F., Winnipeg i.7F. Another impor- 

 tant climatic factor is the high percentage of 

 sunshiny days. This high average of sunshiny 

 days and the fact that on these days the period of 

 actual sunshine is from__i6 to 17 hours make an 

 ideal condition for rapid growth. In fact more 

 rapid growth may be made here than under con- 



