Laserfiche WebLink
<br />. <br /> <br />observed generally range from 30 to 40 degrees below zero. The <br /> <br /> <br />annual mean precipitation averages about 12 to 19 inches, the <br /> <br /> <br />amounts increasing with proximity to the mountains, About 70 <br /> <br /> <br />percent of the annual precipitation falls in the 6-month period, <br /> <br /> <br />April through September, much of it in heavy down?ours accompanying <br /> <br /> <br />summer thunderstorms. The month of May is generally the peak of <br /> <br /> <br />the rainy season. Winter snowfall averages from 2 to 5 feet on <br /> <br />the plains and 4 to 6 feet in the foothills. <br /> <br />MJl..IDAINS AND VAlli.YS <br /> <br />Climatic conditions observed at mountain stations have <br /> <br /> <br />greater differences between stations compared to climatic differ- <br /> <br /> <br />ences observed at plains stations. In general, there is a <br /> <br /> <br />decrease in temperature and an increase in precipitation and wind <br /> <br /> <br />movement with increasing altitude; however, conditions can modify <br /> <br /> <br />this relationship substantially. The diurnal fluctuation is <br /> <br /> <br />small on the mountain slopes and quite large in the valleys. At <br /> <br /> <br />the summits the mean temperatures are low, averaging less than <br /> <br /> <br />32 degrees annually. The low extremes are not more severe than the <br /> <br /> <br />plains, but readings of Zero or lower are much more common. The <br /> <br /> <br />rainfall in the mountain areas depends largely on elevation and <br /> <br /> <br />exposure to mOisture-bearing winds. On the Continental Divide <br /> <br /> <br />precipitation in the form of winter snow is usually substantially <br /> <br /> <br />greater than the summer rain resulting in total annual average <br /> <br /> <br />precipitation values almost double that experienced on the plains. <br /> <br />. <br /> <br />9 <br />