Poison Lake
Lake · Yosemite corridor
Poison Lake sits at 9,213 feet in the Yosemite corridor's high Sierra, a shallow alpine lake exposed to afternoon wind but calmer in early morning hours.
Wind builds consistently through midday and peaks in afternoon. Morning calm typically holds until late morning on all but the windiest days. Cold persists even in warmer months; expect 31 degrees Fahrenheit average. The lake's shallowness and open setting leave no shelter once wind arrives.
Over the last 30 days, Poison Lake averaged 11 mph wind with gusts to 28 mph, and a NoGo Score of 15. The week ahead will track typical spring patterns for this elevation: warming trend through mid-week, afternoon wind acceleration, and light crowds. Plan for morning windows and pack layers.
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About Poison Lake
Poison Lake lies in the high Sierra within the Yosemite corridor at 9,213 feet elevation, accessed via Highway 120 (Tioga Pass Road) from the east or the valley approach from the west. The lake is small and sits in open terrain with minimal windbreak; it anchors a cluster of high-country lakes in the Cathedral Range drainage. Primary approach is foot traffic from the Tioga Pass corridor trailheads. The nearest gateway towns are Lee Vining to the east and Yosemite Valley to the west, both roughly an hour's drive. Parking fills quickly on weekends during the brief summer window when the road is reliably open.
Temperature averages 31 degrees Fahrenheit across rolling 30-day and 90-day windows, with a yearly range from 15 to 46 degrees. Wind averages 11 mph and regularly gusts to 28 mph; afternoon acceleration is predictable and severe. Crowding remains light at a rolling 30-day average of 6, far below busier corridor lakes. Winter snow closes approach roads; late spring and early fall offer the most accessible windows. Summer thunderstorm risk climbs in July and August. The lake typically remains partially iced into late spring and is fully accessible only for a 6 to 8 week window each year.
Poison Lake suits hikers and backpackers seeking solitude at altitude and willing to move early and light. Afternoon paddlers should expect blown-out conditions and poor visibility in wind-driven chop. Fishing pressure is minimal due to the remote access and short season. Most visitors are day-hikers or part of multi-lake backpacking circuits. Experienced high-Sierra travelers plan around the wind by finishing activities by midday and using the lake as a lunch or resupply stop rather than a destination camp. Water is cold year-round; immersion hazard is real.
Nearby Cathedral Range lakes and the Tioga Pass corridor drainage network offer similar conditions and elevation. Mono Basin lakes to the east present a drier, windier alternative at lower elevation. The Yosemite Valley approach via Highway 120 from the west shares road-closure risk but offers a longer drive and often more crowded trailheads. Poison Lake's low base popularity (0.25) reflects its remote access and brutal afternoon wind; it is rarely crowded and appeals to visitors intentionally avoiding busier high-country destinations.