Mammoth Mountain snow report
California's high-altitude outlier: seasons swing from lean to absurd (20 m+787 in+ in record winters). The accumulation range on this page earns its keep here.
United States · North America · live from the weather model at 2424–3369 m7953–11053 ft
Imperial when your device is on a US time zone, metric otherwise, until you choose.
Conditions right now
Read at summit elevation the moment you opened this page.
Hourly windows, accumulation ranges, confidence and travel flags, or the transparent 0–100 Ski Meter score.
Weather data by Open-Meteo.com (CC BY 4.0), adapted for display. Elevations are approximate published figures; forecasts are model estimates, not guarantees.
The mountain right now
The live freezing level drawn on the elevation profile. Above the snow line, precipitation falls and stays as snow.
Terrain shape is schematic; elevations are the resort's approximate published figures.
Ten seasons of snow at Mammoth Mountain
Daily snow depth at this destination's model grid cell, read as ten complete seasons to 31 August 2026. Natural snow only.
In every one of the ten seasons the depth at this cell reached 30 cm12 in and held it for at least a fortnight. The dates above are the median of those ten. The earliest was 8 Nov in 2022-23, the latest 23 Feb in 2017-18.
The band spans the shallowest and the deepest of the ten seasons on each day, and the line runs through the median. It reaches 361 cm142 in, the deepest single day in the record. The dashed line is the 30 cm12 in threshold, and the shaded column is the week Mammoth Mountain traditionally opens, 11 to 17 November.
The index asks a different question of the same ten seasons: in the week this mountain traditionally opens, had 30 cm12 in arrived? All 53 destinations are scored side by side, on one rule.
How the start date is found. For each season this takes the longest unbroken run of days at 30 cm (12 in) or more, and counts it only when that run lasted at least 14 days, because a week of early snow that melts out is not a season starting.
What the model cell is. The reanalysis gives this destination one grid square of roughly 9 km5.6 mi and one elevation for it, being the average of all the terrain inside it. Here that is 3202 m10505 ft, against a resort base of 2424 m7953 ft and a summit of 3369 m11053 ft. Compare the cell against those two before you read any number here as a verdict on the mountain. A reanalysis is a model, not a measurement: it can be too smooth over complex terrain, and it can miss a local storm.
Natural snow only. The model knows about weather. It does not know about snow cannons, and no snowmaking is modelled anywhere. The opening week is traditional, not contractual: it is the window this mountain has historically opened in, not a promise. Daily values run to 31 August 2026.
Take the data. Both tables are free to use and free to republish under CC BY 4.0: one row per destination, and one row per destination per season. Both are in centimetres and metres, whichever units this page shows.
Why it snows here
A volcanic dome at the Sierra crest: atmospheric rivers off the Pacific can deliver metresfeet in a single cycle, and the 3,369 m11,053 ft summit holds it into summer.
Reading Mammoth Mountain like a forecaster
The number that matters most at Mammoth Mountain is the difference between the base (2424 m7953 ft) and the summit (3369 m11053 ft): when the freezing level sits between the two, the mountain is split into rain or wet snow below and dry snow above. The Ski Meter reads the model at both elevations and scores the day with every point accounted for; the full report adds hourly timing, accumulation ranges and confidence tags so you can decide when to travel, not just whether.