CROP ROTATION AND CULTURAL METHODS AT AKRON, COLO. 
WIND VELOCITY 
The wind movement is recorded by a Robinson cup anemometer 
exposed at a height of 2 feet above the ground. The greatest average 
hourly wind velocity, 8.8 miles per hour, was in April. From this 
point the average hourly wind velocity rapidly drops off to the 
lowest point in the year, 5.4 miles per hour, in August. From this 
point the velocity very gradually builds up to 6.7 miles per hour, in 
January and February, from which point it rises rapidly to the peak 
in April. The average monthly wind velocity for the 12 years from 
1912 to 1923, inclusive, is shown in Figure 2. 
As a rule the heavy winds, such as cause damage to the crops, 
spring up during the daylight hours and settle down to comparative 
quiet with the close of the day. Exceptions are noted when high 
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Fig. 2.— Average monthly wind velocity at the Akron Field Station for the 12 years from 1912 to 1928, 
inclusive 
velocity persists for 24-hour periods or longer. Another general 
rule is that the high winds that do the most damage blow during the 
early spring months, when the highest average velocities occur. 
The greatest danger of soil blowing is during the months of January, 
February, and March. Again there are exceptions, one particular 
case being cited as June 18, 1923, when a southeast wind 01 sufficient 
velocity to cause soil movement and very serious damage to growing 
small-grain crops occurred. 
TEMPERATURE 
The climatic factors of this region are all influenced more or less 
by the altitude and the proximity to the mountains, but none perhaps 
more noticeably than the temperature. With an altitude of approxi- 
mately 4,560 feet and the overshadowing influence of the Rocky 
Mountains, the frost-free period is considerably shorter than in 
lower altitudes to the east. The average frost-free period is approxi- 
mately 140 days, extending from May 12 to September 29. Frost 
has been recorded as late in the spring as June 2, this being in 1919, 
