|Yosemite National Park Travel Guide|
YOSEMITE NATIONAL PARK WEATHER
The area of the park has a Mediterranean climate, meaning almost all yearly precipitation normally falls during mild winter and the other seasons are nearly dry (less than 3% of precipitation falls in the typically long, hot summers).
Due to orographic lift precipitation increases with elevation until around 8000 feet (2400 m) when it slowly decreases to the crest.
Precipitation amounts vary from 36 inches (915 mm) at 4,000 feet (1200 m) elevation to 50 inches (1200 mm) at 8,600 feet (2600 m). Snow does not typically persist on the ground until November in the high country. It accumulates all winter and into March or early April.
Temperature decreases with increasing elevation. Temperature extremes are moderated by the fact that Yosemite is only about 100 miles (160 km) from the Pacific Ocean. An anticyclone sits off the coast of California in the summer, sending cool air masses toward the Sierra Nevada that result in clean dry air in the Yosemite area.
Mean daily temperatures range from 25 to 53 °F (-3.9 to 11.5 °C) at Tuolumne Meadows at 8,600 feet (2,600 m). At South Entrance near Wawona (elevation 6192 feet; 1887 m), mean daily temperature ranges from 36 to 67 °F (2.2 to 19.4 °C).
At the lower elevations below 5,000 feet (1525 m), temperatures are hotter; the mean daily high temperature at Yosemite Valley (elevation 3,966 feet; 1209 m) varies from 46 to 90 °F (7.8 to 32.2 °C).
At elevations above 8,000 feet (2440 m), the hot, dry summer temperatures are moderated by frequent summer thunderstorms, along with snow that can persist into July.
The combination of dry vegetation, low relative humidity, and thunderstorms results in frequent lightning-caused fires as well.