RAINFALL AND SNOWFALL. 



593 



The amouuts (»f the iiverage or normal precipitation for each luouth at 

 the five stations in the United States from the date of their establishment to 

 the end of 18-86, and at Winnipeg during the fifteen years 1871 to 1885, 

 are noted in the following table : 



Normal i»ei;ipiiation, in, inchex, for each month of the near. 



From these tables it is seen that the mean annual precipitation of 

 moisture as rain and snow at different places in this district ranges from 18 

 to 32 inches. It is most upon the wooded country east and northeast of 

 the Red River Valley; on that valley plain its average is about 22 inches; 

 but westward it decreases to 19 inches at Bismarck. 



The most plentiful precipitation is during the season of the growth of 

 crops, increasing, on an average for the whole district, from about 2 inches 

 in April to 3 inches in May and 4 inches in Jmie, which is usually the most 

 rainy month; and decrea.sing to about 3 inches in July, nearly the same in 

 August, and 2^ inches in September. But many years depart widely from 

 these averages, there being sometimes during several consecutive 3^ears an 

 excess and during other isolated or consecutive years a deficiency of rain- 

 fall. During the fifteen to twenty years since agricultiu-al settlements were 

 first made in the Red River Valley south of the international boundary, 

 the rainfall and temperature, though showing marked contrasts in different 

 years, have always been so favorable for farming that there has been no 

 instance of failure on this valley plain to secure at least a generally remu- 

 nerative harvest; while most of the years have yielded very abundantly. 



A large portion of the rainfall is brought by thunder showers, which 

 may occur at any hour of the day or night. Terms of cloudy and more 

 or less rainy weather, due to broad storms that sweep from west to east, 

 MON XXV 38 



