10 BULLETIN 30, U. S. DEPARTMENT OF AGRICULTURE. 
monthly averages for the past four years. Strong wmds at Nephi 
are very infrequent and no exceptionally high velocities have been 
recorded. The wind for any one day (24 hours) very seldom exceeds 
a total of 200 miles, while the average velocity does not exceed 10 
miles an hour. The wind is usually from the south and southwest in 
the morning, but during the day it gradually changes until by evening 
it is blowing from the north and northeast. Protracted hot winds are 
practically unknown. 
TEMPERATURE. 
The maximum and minimum temperatures are determined daily at 
the substation from April 1 to October 31, inclusive. The work was 
started June 1, 1908. A maximum and a minimum thermometer, as 
well as an air thermograph, are in constant use during the summer 
months. A summary of the mean, maximum, and minimum tem- 
peratures during April to October, inclusive, for the past four years 
is presented in Table V. 
TABLE V.—Summary of mean, maximum, and minimum temperatures (° F.) at the 
Nephi substation by months from April to October for the years 1909 to 1912. 
Mean. Maximum. 
Minimum. 
ise es aa als Average. ee 1911 ss Average. a 1910|1911/1912) Average. 
Aries Sees ee ee ee 43 | 49 | 44 | 41 44 | 76 | 85 | 74 | 68 78 | 12 | 18 | 13 | 20 16 
Maye eee aes 52 | 56 | 54 | 52 53 | 83 | 92 | 85 | 88 87 | 21 | 28 | 22 | 25 24 
JUNC tee en eee 66 | 68 | 63 | 62 65 | 94 | 97 | 94 | 90 94 | 33 | 40 | 35 | 27 34 
Ait epee see oboe 72 | 73 | 69 | 70 71 | 99 |101 | 95 | 95 97 | 41 | 41 | 36} 41 40 
PAMIPUSL = ene ne See feud a ee) ae) 70 | 95 | 96 | 96 | 95 95 | 46 | 32 | 41 | 42 40 
Sepvcember... 52... - | 59 | 62 | 61 | 54 59 | 85 | 92 | 91 | 84 88 | 27 | 33 | 29} 25 28 
OcriGher- se 49) 48 44 | 44 46 | 79 | 78 | 75 | 78 77 | 12} 23) 1%] 8 15 
! 1 i J } } 
Table V shows that the highest average mean and maximum 
temperatures have been recorded in July, while the lowest have been 
recorded for April and October. Only three of the months, June to 
August, inclusive, have been free from frost. Table VI gives the dates 
of the last spring and first fall frosts and the number of days in the 
frost-free period during each year from 1908 to 1912, inclusive. 
TABLE VI.—Killing frosts at the Nephi substation for the years 1908 to 1912, with tempera- 
tures recorded and length of frost-free period. 
Last in spring. | First in fall. 
| 
i Frost- 
LES Rittinom | Minimum | erveq 
Date. tempera- Date. tempera- | P 
ture. ture. | 
SSS 
ade 4 et ci Days 
1908 3. 22 Sutece soe s cee See es see June 22 30 Aug. 30 31 69 
1A eee eee, aCe eee aa SEL ob tn Le ae May 30 30.5 | Sept. 12 30.5 105 
ISI Af os 1A. bap as ance ch sete eee eee May 16 28 | Oct. 5 29 142 
1s ls Laat Ne gi es eens ees eo ba Fe Re 5 S| i aera May 27 28 Sept. 17] | 29 113 
1) ae ee a ee eS ae ae ee June 16 31 | Sept. 4 30 80 
Orage ae ee ee ee | June 4 | 29.5 | Sept. 14 29.9 | 102 
