Warm to hot, with occasional rain (usually as afternoon thundershowers, especially at the higher elevations). Yosemite Valley & Wawona (4,000 ft / 1,200 m): 87°F (31°C) / 51°F (10°C) Tuolumne Meadows (8,600 ft / 2,600 m): 68°F (20°C) / 35°F (2°C)
Fire & Smoke
Hazy or smoky conditions are common due to fires in the park or elsewhere in California. Lightning-caused fire occurs naturally in the Sierra Nevada, and smoky conditions are natural in summer and fall. The park may also have prescribed fires to mimic natural fires to promote forest health and reduce the risk of larger fires.
Most of the water flowing in Yosemite comes from snowmelt in the high country, so runoff decreases during the dry summer. Peak runoff typically occurs in May or June, with some waterfalls (including Yosemite Falls) often having only a trickle or being completely dry by August. (View a webcam showing Yosemite Falls to see current flow.) Other waterfalls, including Vernal, Nevada, and Bridalveil flow all year; however, flows can be very low by late summer.
While many of Yosemite's higher-elevation trails can remain snowy into June or July, hikes from Yosemite Valley, Wawona, and Hetch Hetchy are usually snow-free by June, and many of these trails can be suitable for backpacking.