Yosemite weather is usually warm to hot in summer, with occasional rain most often falling as afternoon thundershowers, especially at the higher elevations. You can check the average Yosemite climate or get river water levels, wildflower status and so on at the check the National Park Service website.
The High Sierra Camps open in July and August. Spaced 5 to 10 miles apart along a loop trail in the high country, they're so popular that you'll have to get into the reservation lottery to get a spot. Lottery applications are available October 15 to November 30 for the upcoming year. See where the camps are on a map and find out more about how to visit.
Yosemite in Summer: WaterSpring runoff ends in June, on the average. By August, many of the waterfalls are often completely dry, but Vernal, Nevada, and Bridalveil may trickle all year long.
During June and July, you can rent a raft for a float down the Merced River, or bring your own non-motorized kayak or small boat. Rafting is allowed between Stoneman Bridge (near Curry Village) and Sentinel Beach Picnic Area. Rafting is prohibited if there's too much water (more than 6.5 feet deep) - or it's too cold (sum of water and air temperature is less than 100°F).
Yosemite in Summer: WildflowersFlowering season moves into the higher elevations as summer begins, with mid-June through August bringing the best displays to the Crane Flat meadows and along Glacier Point and Tioga Roads. In Tuolumne Meadows, sub-alpine flowers bloom in late summer. Beginning around July, look for little elephant's heads, gentian, penstemon, yarrow, and shooting stars.
If you need help identifying the wildflowers you find in and around Yosemite in Summer, try Wildflowers of the Sierra Nevada and the Central Sierra by Laird R. Blackwell. Compare prices on it here.
Yosemite in Summer: What's OpenThe opening date for Tioga Pass depends on the weather, but is usually around the end of May or start of June. Glacier Point usually opens in early May or late June. See a list of opening/closing dates since 1933.
All of the tours operate in summer, too, including the open-air tram tours and moonlight tours on full-moon nights.
Yosemite Theater offers live evening performances mid-May through October, often featuring Lee Stetson's portrayal of John Muir. Check their schedule.
Yosemite in Summer: PicnicsSummer is a great time for a picnic. You'll save the most money if you bring your picnic provisions from home or pick them up in one of the towns on the way into the park, but you can also get groceries from the store in Yosemite Village. A few good spots to enjoy your goodies:
- Cascade Creek: Even in summer, this spot is seldom crowded. It's on CA 140 east of the Arch Rock entrance station, has picnic tables, restrooms and a swimming hole.
- El Capitan Meadow: You'll find some nice picnic tables just below El Capitan on Northside Drive.
- Sentinel Dome: An easy, one-mile walk from Glacier Point Road takes you to a spot that seems like the top of the world. It's especially pretty here if you arrive about an hour before sunset, but bring a jacket so you don't get too cold and a flashlight in case you get too entranced to leave and need to find you way back in the dark.