16 



DRY FARMING 



8. Geographic Distribution of Precipitation. — The fig- 

 ures reported in the preceding section show that all 

 parts of Western Canada are not equally favored with 

 respect to precipitation. The precipitation map shows 

 the outlines of what may be called the moisture zones in 

 the three Prairie Provinces. While insufficient data are 

 available to insure that the boundaries represented are 

 absolutely correct, yet the map is at least a safe general 

 guide to the precipitation zones. 



9. Monthly Distribution of Precipitation. — The total 

 precipitation per year is not a satisfactory measure of 



Fig. 7. — Monthly Distribution of Precipitation in Canada. 



Note relatively heavy rainfall in the summer months in the Prairie Pro- 

 vinces as compared with low precipitation at Vancouver for the same 

 months and the average distribution throughout the year at Toronto. 



the moisture supply available for crops. The propor- 

 tion that falls in the season the crop is growing is of 

 far greater importance than the annual amount. The 

 following table gives the average precipitation per 

 month for several years at a number of points. 



