6 
BULLETIN 1304, U. S. DEPARTMENT OP AGRICULTURE 
when for four days, beginning with June 1, the minimum tempera- 
tures were 32°, 31°, 32 c , and 32° F. Frost has been recorded as early 
as September 13, this being in 1914. 
The highest mean monthly maximum temperature is 87.6° F., in 
July and the lowest is 36.3° F., in January. The highest mean 
monthly minimum temperature is 57.3° F., in July and the lowest 
is 1 1 .8° F. , in January. The mean monthly maximum and minimum 
temperatures for the 12 years from 1912 to 1923, inclusive, are 
shown graphically in Figure 3. 
90 
SO 
70 
3i 
ZO 
/O 
/PZA 
w/h 
'6/AS 
_yf^// 
V/Afi 
VAf 
/yv// 
a ■ , i i . r i i 1 ; TTti 
^ \ % 
Fig. 3.— Mean maximum and minimum temperatures at the Akron Field Station for the 12 years 
from 1912 to 1923, inclusive 
EVAPORATION 
From April 1 to September 30, inclusive, daily measurements are 
made of the evaporation of water from an open tank 6 feet in diameter 
and 2 feet deep sunk to a depth of 20 inches in the ground. The water 
level is maintained at about the surface of the ground, 4 inches 
below the rim of the tank. The average monthly evaporation for 
the 16 years from 1908 to 1923, inclusive, is shown in Figure 4. 
The average seasonal evaporation was 42.954 inches. This is 
approximately three times the precipitation during the same period. 
The highest average monthly evaporation is in July. Generally the 
evaporation rate is high in seasons when the precipitation is low, 
and low when the precipitation is greater and frequent. 
