Mount Aix is located east of the Cascade crest. Most weather fronts originating in the Pacific Ocean travel northeast toward the Cascade Mountains. As fronts approach, they are forced upward by the peaks of the Cascade Range (orographic lift), causing them to drop their moisture in the form of rain or snow onto the Cascades. As a result, the east side of the Cascades experiences less precipitation than the west side of the crest. 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.[5] Precipitation runoff from Mount Aix drains into tributaries of the Yakima River, thence into the Columbia River.
Geology
Mount Aix is a volcanic complex, mostly referred to as the Mount Aix Volcanic Complex.
^Case, O. D. (1876). The United States: Historical, Descriptive, and Statistical: With an Alphabetical Index to Counties, Mountains, Lakes, Rivers, &o. O.D. Case and Company, Chicago. p. 93.
^Beckey, Fred W. Cascade Alpine Guide, Climbing and High Routes. Seattle, WA: Mountaineers Books, 2008.