Onion Lake· Yosemite· conditions updating now
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Onion Lake

Lake · Yosemite corridor

Onion Lake sits at 10,446 feet in the Yosemite high Sierra, a glacially-fed alpine pool exposed to afternoon wind funnels. Wind-prone but passable on calm mornings.

Today
24
NoGo Score · Go · excellent
Temp
29°F
Wind
15 mph
Vis
10 mi
Precip
0.00"
AQI
24
Cloud
75%

Afternoon wind dominates; the lake tracks the diurnal heating pattern of the high Sierra corridor. Mornings are often flat and cold. By mid-afternoon, sustained gusts push off the surrounding peaks. Water temperature stays near freezing year-round. Crowding is light; the elevation and remoteness keep numbers low.

Over the last 30 days, Onion Lake averaged a NoGo Score of 16.0 with wind averaging 14 mph and temperatures at 24 degrees Fahrenheit. The pattern holds steady through the week ahead. Plan morning visits when wind is subdued and light conditions favour photography or fishing. Afternoon sessions face the 30-mph wind peaks that define this exposed alpine setting.

30 days back / 7 days forward

NoGo Score
avg 15 · today 19
NoGo Score trend for Onion Lake: 30-day average 15, range 8 to 21; 7 days of forecastLine chart showing nogo score over 31 historical days and 7 days of forecast.
30-day average 15 (excellent); range 8 on Apr 13 to 21 on Apr 21. 7-day forecast trends in line with the historical average.
Wind
avg 14 · today 13mph
Wind speed trend for Onion Lake: 30-day average 14 mph, peak 24 mph on Apr 21Line chart showing wind over 31 historical days and 7 days of forecast.
30-day average 14 mph; peak 24 mph on Apr 21. Week ahead peaks at 11 mph on May 10.
Temperature
avg 27 · today 31°F
Temperature trend for Onion Lake: 30-day average 27°F, range 17 to 34°FLine chart showing temperature over 31 historical days and 7 days of forecast.
30-day average 27°F; range 17 (Apr 22) to 34 (Apr 19). Trending warmer.
Crowding
avg 7 · today 11
Crowding trend for Onion Lake: typically quietLine chart showing crowding over 31 historical days and 7 days of forecast.
Typically quiet (avg 7); peak 12 on Apr 3.

Today's score by factor

Weather17
Crowding25
Avalanche0
Fire0
Traffic
Air quality5
Trails20
Seasonality53

About Onion Lake

Onion Lake lies in the high Yosemite corridor east of the Sierra crest, accessible via Highway 120 from Lee Vining or Tioga Pass. The lake sits above 10,000 feet in a sparse, rocky basin typical of the transition zone between true alpine tundra and subalpine forest. The primary approach is a backcountry route; day trips and backpacking trips both use trailheads on the eastern Sierra approach road. The lake is small, intimate, and shallow compared to larger alpine reservoirs nearby. Few people route through here on standard Yosemite Valley itineraries, making it a natural choice for visitors seeking isolation.

Water conditions remain cold year-round, with a 30-year maximum temperature of 39 degrees Fahrenheit and minimums near 10 degrees. The 30-day average wind of 14 mph masks a strong diurnal cycle; calm-wind mornings give way to steady afternoon gusts that routinely reach 30 mph. The NoGo Score averaged 16.0 over the last 30 days, meaning conditions are passable but rarely ideal. Crowding averages only 6 on the popularity scale, a product of the lake's remoteness and the backcountry access required. Late September through early October offers the shortest windows of afternoon wind moderation; winter snows lock out most visitors by November.

Onion Lake suits anglers, backpackers, and photographers who tolerate wind and cold for solitude. The light crowding and sparse infrastructure mean visitors should carry all food, water treatment, and shelter. Camping near the shore is feasible but exposed; windbreaks become crucial in afternoon hours. Kayakers and packrafters should plan launches only on morning windows when the 30-mph peak wind is absent. The lake's shallow margins and rocky bottom make entry tricky; hiking boots with good grip are essential. Experienced high-Sierra travelers recognize that the lake's defining trait is predictability; wind and cold are not surprises but the operating conditions.

The nearest comparable high-alpine lake accessible from the same corridor is Gail Lake, slightly lower in elevation and marginally more sheltered. The Cathedral Range and Mono Basin peaks visible from Onion Lake's shore provide geographic anchors for route-finding and weather forecasting. Visitors already committed to the Yosemite backcountry or the Eastern Sierra corridor should treat Onion Lake as a logical loop extension rather than a destination in isolation. The lake's low base popularity (0.25) reflects its position off the standard park itineraries; that same isolation is its draw for travelers who value wind resistance and emptiness over amenity.

Best times to visit Onion Lake

Best day
Tuesday or Wednesday morning
Best season
Late September to early October
Watch for
Afternoon wind gusts exceeding 30 mph; cold water temperature year-round

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