Hetch Hetchy
Park · 3,813 ft · Yosemite corridor
Hetch Hetchy is a glacially-carved reservoir in Yosemite's Sierra Nevada corridor at 3813 feet. The granite valley floor and dam create a sheltered basin, typically calmer than the high country to the east.
Mornings arrive glassy; afternoon wind funnels off the lake and surrounding peaks by mid-day. The 30-day average wind of 6 mph masks daily swings from near-flat to 18 mph. Head here on calm mornings, skip the afternoon if you're paddling or photographing.
Over the last 30 days, Hetch Hetchy averaged a NoGo Score of 17.0 with temperatures around 46 degrees Fahrenheit and wind at 6 mph. The week ahead shows typical early-summer patterns: rising afternoon thermal wind, increasing crowding as Highway 120 shoulder traffic builds, and stable temps. Water remains cold; expect mist on the reservoir through mid-morning.
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About Hetch Hetchy
Hetch Hetchy sits in the northwest corner of Yosemite National Park, accessible via Highway 120 from the west. The reservoir occupies a U-shaped valley carved by glaciers; Wapama Falls and Rancheria Falls cascade from the north and south walls. The dam itself is the primary landmark and turnaround point for most visitors. Drive time from Moccasin (the nearest small town) is roughly one hour; from Highway 99 near Modesto add another 90 minutes. The park entrance station sits at the mouth of the access road; parking fills early on weekends and holidays.
Conditions at Hetch Hetchy depend entirely on time of day and season. Winter and early spring bring the fewest crowds and lowest thermal winds, but Highway 120 may close for snow. By late spring, afternoon wind becomes predictable and strong; the 365-day maximum wind is 18 mph, typically a mid-afternoon event. Summer sees the reservoir warmest (peaking near 64 degrees Fahrenheit at elevation 3813 feet) and most crowded. The granite amphitheater accelerates wind funneling in the afternoon; mornings with a 30-day average of 6 mph are your planning anchor. Fall offers stable conditions and fewer people until early season snow forces Highway 120 closure again.
Hetch Hetchy suits photographers, kayakers, and day-hikers looking for a less-crowded alternative to Yosemite Valley. The main draw is the dam walk and waterfall views. Experienced paddlers use the reservoir for multi-day trips; day paddlers should launch by 8 AM to avoid afternoon wind. Parking (free, first-come basis) holds roughly 50 spaces at the main trailhead; arrive by 9 AM on weekends or expect to queue or turn back. Smoke from Sierra fires can hang in the valley in late summer; check air quality before the drive.
Yosemite Valley lies 40 miles southeast and is warmer, more crowded, and windier at midday. The Tuolumne Meadows corridor (Highway 120 east) is higher, colder, and typically opens later in spring. If Hetch Hetchy's afternoon wind is too strong, backtrack to the Highway 120 corridor west of the park entrance or plan a Valley day instead. Wapama Falls is the strongest attraction here; winter and early spring offer the most water and the fewest crowds.