Mammoth Lakes Weekend Forecast: June 20-21, 2026
Go. This is about as clean as a Sierra June weekend gets. Temps top out around 70F at lower elevations and hold near 56-58F above 9,000ft. Winds stay under 12mph at the best spots. No precip, clean air across most of the corridor.
Where to Go
Tamarack Lakes Trailhead (9,744ft) is your top pick, scoring NoGo 9.8 with 56F temps and winds barely touching 10mph. From the trailhead off Lake Mary Road, the Tamarack Lakes trail climbs roughly 3 miles through lodgepole forest to a string of granite-rimmed lakes. Expect brook trout and rainbow trout. Small spinners and dry flies both work well in late June as ice-out activity picks up. Start Saturday morning before the Lake Mary Road parking fills.
Hilton Lakes Trailhead (9,843ft) ties Tamarack at NoGo 9.8 and is one of the corridor's most underrated weekender destinations. The trail runs about 4 miles to Lower Hilton Lake with several fish-able basins beyond. Rainbow and brown trout. Lightweight spinning gear or a 4-weight fly rod with small elk hair caddis. Quieter than the Mammoth Lakes basin crowd magnets.
Lake Thomas A Edison (7,647ft) leads the 7,000-9,000ft band at NoGo 9.9 with 59F and 11mph wind. This one is a full day commitment, either via the Mono Hot Springs ferry or the 3-mile walk from Vermilion Valley Resort. Rainbow, brown, and some brook trout in deep water. Troll a Kastmaster or fish the inlet at dusk. Saturday has the quieter crowding average, so go then.
For high-country day hikers, the Rock Creek drainage is dialed in. Rock Creek Lake sits at 9,724ft with a NoGo of 11.7 and the Little Lakes Valley Trailhead at 10,243ft scores 11.3. The valley trail is flat and accessible, passing Marsh Lake, Heart Lake, and Long Lake on the way to Chickenfoot Lake, around 3.5 miles one way. Brook trout and golden trout in the upper basins.
Where to Skip
Valentine Lake Trailhead (7,470ft) scores NoGo 33.3. Skip it this weekend. Bear Ridge Cutoff Trailhead (7,631ft) is at NoGo 30.9. Both are in the same general access corridor and something is pushing those scores well above the band average of 12.6. Hilton Creek Trailhead (7,257ft) sits at NoGo 20.0 despite reasonable weather, so take the extra elevation and start from Hilton Lakes Trailhead instead.
Virginia Lakes Trailhead (9,770ft) scores NoGo 19.0 with AQI 37, the highest air quality index on the list. That AQI reading clusters with the Lee Vining and Mono Lake area numbers, suggesting some eastern-side particulates. If you're coming up Highway 395 from the south, stick to the Mammoth and Rock Creek drainages rather than continuing north toward the Virginia Lakes turnoff.
Bottom Line
Get above 9,000ft Saturday morning and you will have one of the best June weekends the Eastern Sierra can offer.
Published · Weekend of to