McClellan Butte is located in the
marine west coast climate zone of western
North America. Most
weather fronts originate in the
Pacific Ocean, and travel northeast toward the
Cascade Mountains. As fronts approach, they are forced upward by the peaks of the Cascade Range, causing them to drop their moisture in the form of
rain or
snowfall onto the Cascades (
Orographic lift). As a result, the west side of the Cascades experiences high precipitation, especially during the winter months in the form of snowfall. During winter months, weather is usually cloudy, but, due to high pressure systems over the Pacific Ocean that intensify during summer months, there is often little or no cloud cover during the summer.
Precipitation runoff from McClellan Butte drains into the
Snoqualmie River. ==See also==