Intermountain West Climate
The climate of the Intermountain West (Colorado, Utah, and Wyoming) is influenced by several key factors:
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Mid-continental location, distant from oceanic moisture sources, leads to abundant sunshine, low humidity and large temperature changes daily and seasonally compared to locations nearer the coasts.
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High average elevations also contribute to large temperature changes; the thin air at high elevations heats up faster and cools down faster.
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Complex mountainous topography leads to abrupt gradients in both temperature (cooler) and precipitation (wetter) with increasing elevation, drier rain-shadows downwind of mountain ranges, and cold-air pooling in deep valleys and basins.
As a result, the region has enormous spatial variability in climate, with annual precipitation ranging from about 6" to 80" (see figure at right) and mean annual temperatures ranging from around 20°F in the high mountains to 60°F in southern Utah.
The seasonal distribution of precipitation also varies greatly around the region, with the mountains generally seeing a winter peak. Except at the lowest elevations, most or all of the cool-season (October to March) precipitation falls as snow, which has important implications for the region's water cycle.
University of Colorado Boulder 
