8 BULLETIN 33, U. S. DEPARTMENT OF AGRICULTURE. 
The average wind velocities in miles per hour during the months 
from May to August for the years 1908 to 1913, inclusive, are pre- 
sented in Table ITI. 
TABLE III.—Average wind velocity at the Dickinson substation, by months, 
from May to August for the years 1908 to 1913, inclusive. 
[Data (in miles per hour) from the records of the Biophysical Laboratory of the Bureau of Plant Industry.] 
Month. | 1908 | 1909 | 1910 | 1911 | 1912 1913 | Average. 
| 
May esse cons wee 4 Sent ian ee ae | oe Bho: O26") one de aad 8.9 
GUNG Seb 8 A eee 4 ae eee ee 82912720 6.7 7.3 6.6) 7.9] 7.4 
Hinky p Sen sh Ga! Se eo eek eer Aue 4.9 5.6 ag Ba aa res 5.6| 6.4 | 6.0 
ATIETISE = sas ec C2 oe Reon wee oh 5.9 Ee eS ee ad fare 5.8 
AVerAb et soared Cae See ete 6.6 6.7 6260? nna eee 7.0 | 7.0 
| | 
Table III shows the average wind velocity at Dickinson to be 7 
miles per hour from May 1 to August 31. It also shows that there 
is a general decrease in the velocity of the wind from May to August. 
The greatest seasonal velocity was recorded in 1911, which was the 
year of least rainfall and greatest evaporation. During July of that 
year protracted hot winds occurred, which caused the velocity for 
that month to be unusually high. The low yields recorded in 1911 
were due largely to injury to the growing crops by these winds. 
The wind for any one day (24 hours) very seldom exceeds a total of 
500 miles, while the hourly velocity seldom exceeds 30 miles an hour. 
The wind is usually from the northwest or the southeast. 
TEMPERATURE. 
A maximum and minimum thermometer and a dry-bulb ther- 
mometer are in constant use at the substation during the summer 
months. A summary of the mean, maximum, and minimum tem- 
peratures during April to August. inclusive, for the past seven years 
is presented in Table IY. 
TaBLe IV.—Summary of mean, maximum, and minimum temperatures at the 
Dickinson substation, by months, for the crop season (April to August) of 
the years 1907 to 1913, inclusive. 
[Data (in °F.) from the records of the Biophysical Laboratory of the Bureau of Plant Industry. ] 
April. May. June. July. | August. 
B di4 si¢| gj¢ aig = | € Seasonal 
car. ) |8]3 all =| 5 | See = | 5 | mean. 
48 Blea |S 84 lS 1S | ae) 3oqeeaesoleseas 
See se es be ead ee ea eae! ee ee 
Oo] 38] -v ) So | ex ° Soj|la| oO] os = ) 3 = 
ee ee ei ree ee =o ea eran a bh = 
MODE Reeth es eee et 35 | 69 | 5 | 43 | 74] 11 | 56] 86} 30 | 64 | 93 | 44 | 64 | 97 | 34 52 
AOD R a ea aoe CEI Be | 43 | 88 |—6 | 49 | 74 | 20 | 59 | 88 | 37 | 70| 97 | 40 | 64 | 100 | 27 | 58 
MOOO Seo oe ak ees 34 | 62| 4] 51] 86 | 20! 62 | 94) 41 | 67| 93] 46] 68| 94] 38 | 56 
AOIO oe Ake ae eo he 49 | 89 | 18 | 50 | 80 | 24 | 64 97 | 29 | 69 | 107 | 41 | 61 97 | 33 59 
7 YY 1 DeSean Be a Si ey 39 | 8&7 6 | 52) 86 | 23 | 65 | 97 | 41 | 66 | 101 | 37 | 60 | 95] 28 56 
11D eee eRe ee 44 | 75.) 16 | 52 | 82 | 32 | 61 | 97 | 32 | 65] 91} 36 | 64) 87 | 41 57 
NOISE: So eee eee eee 46 | 85 | 19 50 | 92 | 24 | 63 | 97 | 35 | 65 96 | 40 | 69} 97 | 42 59 
AW OTAlG ae eres | 31 | 79| 9| 50 67 | 97 | 41 | 64 | 95 | 35 57 
A EPP 93 | 35 
