Yosemite NP Home Page Yosemite National Park Yosemite National Park embraces almost 1,200 square miles of scenic wild lands set aside in 1890 to preserve a portion of the central Sierra Nevada that stretches along California's eastern flank. Weather can change rapidly during all seasons of the year.
Elevation plays a major role in temperature and precipitation.
Most of the moisture comes in the months of January, February and March, and the winter climate is relatively mild. Sierra summers are typically warm and dry. April and November are transitional months, when warm, sunny days can suddenly become stormy. Clouds can build up during the summer to produce spectacular thunderstorm activity. Always include some kind of rain gear.