i6 
The Colorado Experiment Station 
TABLE V.—FROST DATA FOR REPRESENTATIVE COLORADO STATIONS.—CONT. 
(Data available up to and including year 1915). 
Station 
County 
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m .2 
Rangely . 
.Rio Blanco. ... 
5050 
May 
16 
June 23 
Aug. 21 
Aug. 31 
115 
88 
Rocky Ford . . . 
.Otero . 
4177 
Apr. 
27 
May 
15 
Oct. 8 
Sept. 13 
164 
140 
Saguache . 
.Saguache . 
7740 
May 
26 
June 18 
Sept. 25 
Sept. 10 
124 
93 
Salida. 
. Chaffee . 
7035 
May 
26 
July 
6 
Sept. 17 
Sept. 6 
113 
68 
San Luis . 
. Costnia . 
7794 
July 
5 
July 
6 
Sept. 20 
Sept. 5 
106 
68 
Sapinero . 
. Gunnison .... 
8125 
June 17 
June 30 
Sept. 15 
Sept. 6 
91 
81 
Silverton . 
. San Juan.... 
9400 
June 
3 
July 
9 
Aug. 8 
Aug. 26 
65 
55 
Spicer . 
.Jackson . 
8700 
June 27 
July 
11 
Aug. 27 
Aug. 31 
61 
34 
Steamboat Spgs. 
.Routt. 
6683 
July 
7 
July 
30 
Aug. 30 
Aug. 2 
57 
24 
Sterling . 
. Logan. 
3892 
May 
6 
May 
22 
Sept. 27 
Sept. 5 
144 
127 
Sug-ar Loaf ... 
. Boulder . 
7800 
May 
25 
June 14 
Sept. 18 
Aug. 25 
116 
93 
Telluride . 
. San Miguel. .. 
8756 
June 29 
July 
27 
Sept. 5 
Aug. 18 
74 
66 
Trinidad. 
.Las Animas... 
5994 
May 
1 
May 
23 
Oct. 11 
Sept. 22 
162 
133 
Victor. 
.Teller . 
10100 
June 
4 
July 
3 
Sept. 21 
Sept. 5 
111 
76 
Wagon Wh. Gap 
. Mineral . 
9610 
July 
11 
July 
31 
Aug. 19 
Aug. 1 
25 
1 
Walden. 
.Jackson . 
8050 
July 
6 
July 
20 
Aug. 31 
Aug. 14 
56 
25 
Westcliffe. 
. Custer . 
7864 
July 
10 
July 
29 
Oct. 14 
Aug. 1 
101 
67 
Whitepine . 
.Gunnison .... 
9500 
June 
3 
July 
9 
Aug. 7 
Aug. 22 
64 
46 
Wray . 
• Yuma . 
3512 
May 
6 
May 
27 
Oct. 3 
Sept. 12 
150 
124 
Variations in Frost Dates and Length of Frostless Season .— 
It is of value to know the frequency of late frosts in the spring, 
of early frosts in the autumn and also of short frostless seasons. 
Variation in the length of frostless seasons for a number of 
Colorado stations is shown in Fig. 6. In some localities, there is 
not much departure from the normal from year to year, and the 
farmer or fruit-grower finds the seasons much the same from year 
to year, while in other localities there is very marked variation, 
which leads to much uncertainty and uneasiness on the part of the 
farmer or fruit-grower. 
Effect of Altitude on Length of Frostless Season. —The aver¬ 
age length of the frostless season for all stations in the different 
altitudinal zones is shown in the accompanying table. 
TABLE VI.—ALTITUDE AND LENGTH OF FROSTLESS SEASON. 
Feet Days 
Below 5000 . 146 
5000—6000 . 138 
6000—7000 . 113 
7000—8000 . 98 
8000—9000 . 56 
A pronounced difference exists between the average length of 
the frostless season of stations having approximately the same 
