Onion Valley Trailhead
Trailhead · 9,185 ft · Eastern Sierra corridor
Onion Valley Trailhead sits at 9,185 feet in California's Eastern Sierra, a high alpine staging point for the Inyo drainage. Early-season snow and afternoon wind define the approach.
Afternoon wind arrives by mid-day most weeks; mornings are calmer. Temperature swings sharply between sun and shade. The exposed 9,185-foot elevation means cold soaks linger into spring. Afternoon thermals and basin funneling drive sustained gusts.
Over the last 30 days, the 30-day average wind has held at 14 mph, with peaks near 49 mph on exposed days. The 30-day average temperature sits at 27 degrees Fahrenheit. The chart below plots the last 30 days and forecasts 7 days forward across NoGo Score, wind, temperature, and crowding. Watch for rapid afternoon swings typical of high Sierra ridges.
30 days back / 7 days forward
Today's score by factor
About Onion Valley Trailhead
Onion Valley Trailhead lies 25 miles west of Independence, California, accessed via Highway 395 and the Onion Valley Road (State Road 18P), a steep switchback climb that often closes until late spring due to snow. The trailhead sits at the head of a glacial cirque in the Inyo range, facing east into the Owens Valley. From Independence, drive north on Highway 395, turn west onto Market Street (which becomes Onion Valley Road), and climb 15 miles to the large lot and ranger station. The drive takes roughly one hour in clear conditions. Winter access depends entirely on road maintenance; call the Inyo National Forest for current conditions. The site serves as the primary staging area for the Kearsarge Pass watershed and High Sierra backcountry loops.
Conditions at Onion Valley pivot on elevation and season. The 30-day average wind is 14 mph, with maximum gusts reaching 49 mph; sustained afternoon thermals off the valley floor accelerate by 2 to 3 p.m. most days. Temperature averages 27 degrees over the past month, but the rolling 365-day record shows a range from 12 degrees in winter to 44 degrees in peak summer. Spring and early summer bring rapid snowmelt, high water crossings, and persistent afternoon wind. Late summer and early fall offer the most stable window: calmer mornings, warmer days above 40 degrees, and reduced avalanche hazard. Winter and early spring carry active avalanche terrain in the upper drainages; the Eastern Sierra Avalanche Center (ESAC) monitors the zone. Crowding averages 7 out of 10 over the last 30 days, spiking when Highway 395 conditions improve and the road opens fully.
Onion Valley suits climbers, backpackers, and day hikers targeting the High Sierra crest and Kearsarge Pass. The exposed 9,185-foot elevation and pronounced afternoon wind pattern demand early starts. Experienced visitors depart by dawn, complete ridge crossings or open traverses by early afternoon, and descend before thermals peak. Snow lingers into June most years; avalanche awareness and microspike or crampons are essential for steep approach gullies. Parking fills on weekends throughout summer; arrive before 8 a.m. or plan a weekday trip. The site's high base popularity (0.4) reflects its role as a gateway to major cross-Sierra routes. Cell service is absent or marginal; no services exist at the trailhead. The ranger station provides water and permits but no fuel or food.
Nearby alternatives include Shepherd Pass Trailhead, 30 miles south via Highway 395 and an equally steep approach road, which offers similar High Sierra access with marginally lower crowding and a slightly different drainage character. Mather Pass lies due west and is accessible from the Onion Valley cirque for experienced scrambler-climbers. The Independence/Lone Pine corridor along Highway 395 hosts dozens of smaller, lower-elevation day-hike access points that avoid avalanche terrain and offer warmer conditions during shoulder seasons. Winter-access seekers should consider Cottonwood Pass or Shepherd Pass, both of which hold roads open slightly longer. Onion Valley remains the most direct and popular jumping-off point for first-time visitors to the High Sierra crest.