Purple Lake
Lake · 9,934 ft · Mammoth Lakes corridor
Purple Lake sits at 9,934 feet in the Mammoth Lakes corridor of California's Sierra Nevada. This glacially-fed alpine lake sits sheltered by surrounding peaks and typically runs calmer than the lower basins to the west.
Wind funnels off the lake by mid-afternoon most days, building from near-flat mornings. Cold water and exposed terrain mean hypothermia risk is real if you go in. Head here on calm mornings; afternoon sessions bring sustained gusts and chop.
Over the last 30 days, Purple Lake averaged a NoGo Score of 36 with an average wind of 14 mph and temperatures around 23 degrees Fahrenheit. The week ahead will track similar patterns; mornings typically offer the best window before afternoon wind picks up. Watch the 7-day forecast for any drop below the 30-day average as a signal to prioritize early departure.
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About Purple Lake
Purple Lake lies in the high-Sierra Mammoth Lakes corridor, northeast of Inyo National Forest's central ridge. Access is via Highway 395 south from Lee Vining or north from Bishop; from Highway 395, head west on Highway 120 toward Tioga Pass, then follow the High Sierra Camps road and local signage toward the Mammoth Lakes basin. The lake sits at 9,934 feet elevation, making it a full alpine environment with avalanche terrain on approach and surrounding slopes. Parking is limited; plan for early arrival on weekends.
Spring and early summer (late April through mid-June) bring lingering snowpack and variable conditions as the Sierra transitions out of winter. Average temperatures hover around 23 degrees Fahrenheit; the rolling 30-day average wind sits at 14 mph, with gusts reaching 43 mph on exposed days. Winter conditions persist through May in most years; avalanche terrain is active, and stable footing depends on freeze-thaw cycles. By late July, snow recedes and temperatures climb into the high 30s to mid-40s. Late September through early October offers the most stable weather window, with fewer afternoon gales and lower crowding.
Purple Lake suits experienced alpine paddlers, mountaineers, and hikers comfortable with early-season exposure. The lake drains into the Cascade Range proper; its watershed feeds major creeks downstream. Parking constraints and weather volatility mean experienced visitors plan for a Tuesday to Wednesday visit rather than weekends; the rolling 30-day crowding average sits at 4, but weekend spikes are sharp. Bring avalanche awareness and cold-water rescue gear if paddling. The wind profile demands respect; conditions flip from glassy to hazardous within two hours of sunrise.
Nearby alternatives include Mamie Lake and Gem Lake, both lower in elevation and typically warmer by 5 to 10 degrees Fahrenheit. The Mammoth Lakes basin offers more sheltered water in Horseshoe and Twin Lakes to the south. For alpine purists, the lakes along the Cascade Range crest trade extreme exposure for cleaner water; Purple Lake straddles both worlds. Approach via Highway 120 is scenic but closes seasonally; verify pass conditions before committing to a trip.