32 DRY FARMING 



ing wheat very far north in Alberta seems promising. 

 How profitable it may be, the average date of the first 

 fall frost and the percentage of seasons that are free 

 from summer frosts will largely determine. 



21. Wind Velocity. The wind velocity averages higher 

 on the open plains than in the park belt and wooded 

 areas. In some seasons it does serious injury to tender 

 plants and shrubs by causing the soil to drift. Accord- 

 ing to Cross* the average velocity ranges in different 

 parts of the West from 5.1 to 13.3 miles per hour, while 

 the average maximum ranges from 30 to 57 miles per 

 hour. 



22. The Chinook Wind. The temperature of the south- 

 westerly winds is the highest and that of the north- 

 easterly the lowest. The Chinook, a Avarm southwest 

 wind, is often responsible in winter for removing the 

 snow covering very soon after it comes. This is per- 

 haps favorable for the rancher but not so for the crop 

 grower. In summer this wind sometimes does serious 

 injury to crops in southern Alberta and southwestern 

 Saskatchewan, occasionally as far east as Moose Jaw and 

 Saskatoon. It is reported that it is occasionally felt in 

 milder form as far north as the Peace River Valley and 

 upper Mackenzie basin. 



23. Humidity of the Wind. Little data is available 

 concerning the humidity of the atmosphere in these 

 winds but experience has shown that the southwest and 

 west ones are very dry while those from other directions 

 are generally more humid, especially the east winds. 



* In "Climate and Rainfall", by ,T. F. Cross in "Prairie Provinces 

 of Canada", Sells Ltd. 



