Colorado Climatology i i 
cst and lowest temperature during the month gives the monthly 
range. At the end of the year we obtain the annual mean tempera¬ 
ture, the monthly and daily means of temperature, the daily, monthly 
and yearly range of temperature. 
The rain gage which is used to measure the precipitation has 
an inner receptacle that magnifies the amount ten to one, making it 
possible to read to one hundredth of an inch with accuracy, and 
though the different elements vary considerably from month to 
month and year to year, the averages of all the years and of all the 
separate months afford a fairly accurate estimate of what we may 
expect each year and each month. It is only from the average of a 
long series of observations that an accurate opinion may be formed 
of the temperature and precipitation of a locality, and also what is of 
equal importance, the extremes that are liable to come. The records 
in this bulletin are brought up to the end of 1911 and extend far 
enough back to give the average results and a fairly good knowledge 
of the climate of those portions of the State reported upon. That 
it is possible to place before the public the data from these stations 
depends upon a great deal of patience, care and accuracy on the part 
of the observers, and much credit is due those observers whose only 
recompense has been giving to the public a portion of their time and 
labor, in some cases twenty to twenty-five years, in order that we 
may have a knowledge of the climatology of the State in which we 
live. 
Throughout all tables, unless otherwise stated, Fahrenheit de¬ 
grees have been used. 
Some of the qualities that make for health, comfort, and man’s 
enjoyment of life are: abundance of sunshine; a pure, dry air; 
clear skies giving a wide daily range of temperature; freedom from 
heat prostrations; a low humidity, making us exempt from the raw, 
chilly mornings or penetrating cold, giving in its place a dry, bracing 
cold, usually attended by sunshine ; and a favorable sensible tem¬ 
perature, tending to modify the cold of winter as well as the heat 
of summer. In winter it is usually warm in the sunshine, and in 
summer it is always cool in the shade. There is seldom a night in 
the year when a blanket covering is not comfortable. The air is 
healthier than at a lower altitude, because it is cleaner. Bacteria 
decrease rapidly as we rise in the air. Such a bracing, invigorating 
climate stimulates the people as a whole, to their best efforts in any 
line of work or endeavor. 
THE ARKANSAS VALLEY SUBSTATION. 
This station is located near Rocky Ford, Colorado, and was 
established by the Colorado Experiment Station in 1888, and 
records have been taken since that time. The elevation of the sta- 
