42 DRY-FARMING 
Snowfall 
Closely related to the distribution of the rainfall 
and the average annual temperature is the snowfall. 
Wherever a relatively large winter precipitation 
occurs, the dry-farmer is benefited if it comes in the 
form of snow. The fall-planted seeds are better 
protected by the snow; the evaporation is lower and 
it appears that the soil is improved by the annual 
covering of snow. In any case, the methods of 
culture are in a measure dependent upon the amount 
of snowfall and the length of time that it lies upon 
the ground. 
Snow falls over most of the dry-farm territory, 
excepting the lowlands of California, the immediate 
‘Pacific coast, and other districts where the average 
annual temperature is high. The heaviest snowfall 
is in the intermountain district, from the west slope 
_of the Sierra Nevadas to the east slope of the Rockies. 
The degree of snowfall on the agricultural lands is 
_ very variable and dependent upon local conditions. 
Snow falls upon all the high mountain ranges. 
Temperature 
With the exceptions of portions of California, 
Arizona, and Texas the average annual surface 
temperature of the dry-farm territory of the United 
States ranges from 40° to 55° F. The average is 
