8 
BULLETIN 398, U. S. DEPARTMENT OF AGRICULTURE. 
Measurements of the wind velocity have been taken since 1910 at 
the Judith Basin substation by the Biophysical Laboratory of the 
Bureau of Plant Industry. The records are taken during six months , 
April to September, inclusive. The anemometer stands near the 
evaporation tank, at a height of about 2 feet above the surface of 
the ground. Table VII gives the average wind velocity from April 
to September in the six years from 1910 to 1915, inclusive. 
Table VII. — Average wind velocity (in miles per hour) at the Judith Basin substation. 
Moccasin, Mont., by months, from April to September of each year from 1910 to 1915, 
inclusive. 
[Data from the records of the Biophysical Laboratory of the Bureau of Plant Industry.] 
Year. 
Apr. 
May. 
June. 
July. 
Aug. 
Sept. 
Average. 
1910 
9.0 
6.8 
6.3 
5.9 
6.0 
4.0 
6.33 
7.8 
8.0 
5.4 
5.9 
5.9 
5.3 
6.38 
1912 
6.6 
7.6 
5.7 
5.1 
6.4 
6.7 
6.35 
1913 
8.7 
6.5 
5.3 
5.0 
5.4 
6.5 
6.23 
1914 
6.3 
7.5 
6.4 
5.5 
6.0 
7.2 
6. 48 
1915 
7.6 
7.5 
6.6 
5.1 
4.9 
5.9 
6.26 
7.7 
7.3 
6.0 
5.4 
5.8 
5.9 
6. 35 
Table VII shows that April has the highest average wind velocity ? 
7.7 miles per hour. The average wind velocity decreases through 
May, June, and July, but increases again slightly in August and Sep- 
tember. The 6-year average velocity in the six months is 6.35 miles 
per hour. 
TEMPERATURE. 
Table VIII gives the mean, maximum, and minimum tempera- 
tures at the Judith Basin substation by months from April to Sep- 
tember of each year from 1909 to 1915, inclusive. The highest aver- 
age mean temperatures occur in July and August, 63° F., and the 
highest average maximum in August, 77° F. Temperatures as high 
as 95° F. are rare in the Judith Basin. When hot weather occurs it 
lasts for only a short time. Hot, drying winds are uncommon. In 
only one year since the station was started have hot winds done any 
damage to the growing crops. 
Table VIII. — Mean, maximum, and minimum temperatures (°F.) at the Judith Basin 
substation, Moccasin, Mont., by months, from April to September of each year from 
1909 to 1915, inclusive. 
[Data from the records of the Biophysical Laboratory of the Bureau of Plant Industry.] 
Year. 
April. 
May. 
June. 
July. 
August. 
September. 
1909. 
1910. 
1911. 
1912. 
1913. 
1914. 
1915. 
63 38 
65 37 
59 | 38 
Average . . 
55 
30 
49 
61 38 
58 
63 
76 
77 
■is 
53 65 40 
