The Regional Adaptation of Corn in Nebraska 
15 
as a summary expression of temperature, relative humidity, and 
wind velocity; and (3) absorptive and retentive character of 
the soil for moisture. 
Fig. 7 — Average annual precipitation for the different sections of Nebraska. 
(Inches.) 
MEAN ANNUAL PRECIPITATION 
As shown in Figure T, the annual precipitation falls rather 
gradually from 32 inches in the extreme southeast to 16 inches 
in the extreme western part of the State. In the eastern two- 
thirds of the State the lines of equal rainfall run in a some- 
what northeasterly direction. The character and distribution 
of the rainfall is rather uniform thruout the State, being of 
the torrential type and coming largely during the crop growing 
season. (Table 1.) 
Table 1 . — Normal Monthly Distribution of Rainfall in Ne- 
braska. Average of Entire State for Thirty Years. 
Month 
Inches 
Month 
Inches 
January 
68 
July 
3.51 
February 
71 
August 
2.62 
March 
1.16 
September 
1.84 
April 
2.40 
October 
1.49 
Mav 
3.60 
November 
.68 
June 
3.93 
December 
.69 
Average annual rainfall, 23.31 inches. 
EVAPORATION RATE 
The power of the atmosphere to evaporate water has a 
marked influence upon the effectiveness of the rainfall. Data 
