Colorado Climatology 
7 
make it seem cooler than the temperature of the air would in¬ 
dicate, especially on a cold day. 
YEARS OF STUDY SHOWS CLIMATE NOT CHANGING 
We often hear the statement made that the climate is 
changing, and the popular belief that such is the case can only 
be explained by the generally sliort and defective memories of 
people who through exposure to a few severe storms in the 
past, or inconvenience, or perhaps loss from a few of them, 
unintentionally exaggerate the severity and frequency of 
their occurrence. Although large fluctuations occur in differ¬ 
ent years with some indication of periodical terms, especially 
in Colorado, where the range of temperature is great, there 
seems to be no progressive change. These fluctuations are 
large and often in the same direction for several successive 
years. 
In the meteorological data for the last one hundred years, 
the record of some places extending still* further back, there 
is nothing to support the idea of any permanent change in the 
climate having taken place, or that any change is about to take 
place, and the mean temperature shows no indication of any 
permanent change either warmer or colder. The small modifi¬ 
cations claimed by cultivation, the planting of trees, and the 
erection of buildings, even of a large city, are too small to alter 
the mean temperature of any section of the country. 
Colorado being an arid state, the amount of precipitation 
is at all times a vital question. Liability to a marked defici¬ 
ency in rainfall in any region is a matter of grave concern to 
those engaged in agriculture and other interests. We often 
hear it stated that the rainfall is changing, that the settling up 
of the country and the planting of trees and building of reser¬ 
voirs, forming lakes and wet places throughout the country, 
is causing an increase in the amount of our precipitation, but 
long series of observations taken at different places over the 
world, do not bear out that claim. 
That the forest that cover the sides of the mountains exert 
a retarding influence in the melting snow and the drainage of 
the water, thus prolonging the period in which the same may 
be made available in irrigation, is true. Complaints are heard 
that the snows do not lie as long in summer as they used to 
before so much of the forest cover was removed, but there is no 
reason to believe that the amount of snow falling on the high 
mountains, or plains either for that matter, is different from 
that of ages ago. In general, the precipitation seems to de- 
