10 BULLETIN 1039, U. S. DEPARTMENT OF AGRICULTURE. 
TEMPERATURE. 
The temperatures at the Belle Fourehe Experiment Farm are re- 
corded daily throughout the year by means of maximum and mini- 
mum thermometers. During the growing season a thermograph was 
also used. The mean monthly temperatures in degrees Fahrenheit 
from 1908 to 1919, inclusive, are shown in Table IV. 
Table IV. — Mean monthly temperatures (in degrees F.) at the Belle Fourehe 
Experiment Farm during the 12-year period from 1908 to 1919, inclusive. 
Month. 
January... 
February. . 
March 
April 
May 
June 
July 
August 
September. 
October . . . 
November. 
December. 
Average. 
1909 
43 
1910 
1911 
1912 
1913 1914 
1915 
43 42 
42 
1919 
Aver* 
44 
The average annual mean temperature was 44°. The absolute mini- 
mum during this period was —37° F. in January, 1916, and the abso- 
lute maximum was 109° F. in July, 1910. The temperature has not 
been a limiting factor in the yields of most of the spring grains. 
The grain sorghums and late varieties of proso, however, usually 
were frosted before fully mature. Winter wheat suffered some injury 
from low temperatures nearly every year and during the winter of 
1917-18 was almost completely destroyed. 
Table V. — Dates of killing frosts, the last in spring and the first in autumn, 
at the Belle Fourehe Experiment Farm, for each year from 1908 to 1919, 
inclusive. 
Last frost in 
spring. 
First frost in 
fall. 
Frost- 
free 
period. 
Year. 
Last frost in I First frost in 
spring. fall. 
Frost- 
Year. 
Date. 
Tem- 
pera- 
ture. 
Date. 
Tem- 
pera- 
tut e. 
Date. 
Tem- 
pera- 
ture. 
Date. 
Tem- 
pera- 
ture. 
free 
period. 
1908 
1909 
1910 
1911 
1912 
1913 
1914 
Mav 20 
May 17 
May 23 
Mav 11 
May 4 
Mav 6 
May 13 
°F. 
29 
26 
31 
30 
32 
32 
30 
Sept. 26 
Sept. 23 
Aug. 25 
Aug. 27 
Sept. 23 
Sept. 24 
Oct. 5 
°F. 
22 
31 
32 
32 
32 
29 
28 
Days. 
129 
128 
93 
107 
141 
140 
144 
1915 
1916 
1917 
1918 
1919 
Average. 
Mav 21 
Mav 16 
May 31 
May 21 
June 1 
May 18 
°F. 
32 
31 
30 
31 
32 
Sept. 14 
Sept. 14 
Oct. 7 
Sept. IS 
Oct. 9 
Sept. 21 
°F. 
31 
28 
20 
28 
12 
Days. 
115 
121 
145 
120 
130 
30.5 
28 
126 
The dates and minimum temperature of the last spring and first 
autumn frosts each year are shown in Table V. The latest spring 
