❄ PassCast
Mountains / Sierra

Mammoth Mountain CA

7,953–11,053 ft · long-term average 400" per season · window ticket ~$249 · prime window Jan–Feb

PassCast reseeded 2026-07-10 · season 2026-27

The short answer: PassCast projects a median of 346" at Mammoth Mountain for 2026-27 — 106% of a typical season — with a skiability rating of 66/100, ~17 powder days, and Jan–Feb as the prime window. Updated daily from 10,000 simulations.

66SKIABILITY / 100Deep & reliable
Snow quantity 35%75
Season lean 30%57
Powder days 20%68
Bust risk 15%57
Median sim
346" (106% of typical)
P(above typical)
55%
Powder days
~17 (6"+ days)

80% of simulated seasons land between 151" and 605". Reseeded daily as ENSO observations, CPC outlooks, and SEAS5 runs update.

10,000 simulated 2026-27 seasonsENSO-weighted resampling of 36 real seasons (1990–2026) at Mammoth Mountain, tilted by the live seasonal outlook

100"200"300"400"500"600"700"800"900"1000"1100"1200"1300"1400"1500"1600"1700"P10 151"P50 346"P90 605"typical 327"

Highlighted bars span the middle half of outcomes (P25–P75). The yellow dashed line is a typical season — the median of the last 36 at this mountain.

What's driving this forecast

ENSO: El Niño favored (99%)

The 2026-27 season is simulated by resampling Mammoth Mountain's historical seasons weighted toward El Niño analog years. NOAA CPC El Niño Advisory (June 11, 2026): El Niño conditions are present and expected to strengthen into winter 2026-27, with a 63% chance of a very strong event (Niño3.4 ≥ +2.0°C) during Nov-Jan. CPC DJF strength odds: very strong 46%, strong 33%, moderate 16%. IRI (June 22) concurs at 98% El Niño for DJF. Latest observed ONI (AMJ 2026): +1.0.

Regional ENSO signal: favorable (weak)

Tahoe straddles the storm-track pivot: record 1982-83 El Niño snow, but the 1987 and 1992 strong events were droughts. High variance, low predictive value. Applied as a +2% tilt at partial weight.

Pre-season: climate drivers only

Day-to-day weather models have no skill this far out, so the near-term forecast contributes 0% weight today. The simulation leans entirely on ENSO-conditioned climatology — exactly what an honest seasonal outlook should do in summer. Weighting shifts toward live forecasts as opening day approaches.

The regional readSierra · from the 2026-27 outlook

Strong El Niño is the Sierra's classic wet card, but it's south-weighted and high-variance: 1982-83 and 1997-98 were all-timers, 2023-24 finished above normal, yet 2015-16 — the 'Godzilla' El Niño that was supposed to end the drought — gave Tahoe merely an average year. Mammoth and the southern Sierra carry the continent's best odds of an above-average season outside the Southwest; Tahoe is a better-than-even wet bet with real rain-line risk below 7,000 feet. Expect a back-loaded winter — January through March is when strong-Niño Sierra seasons detonate.

Full global outlook →

Month by monthENSO-conditioned analog medians vs a typical month — when this season should deliver

Nov116%Dec78%Jan104%Feb94%Mar110%Apr102%
Typical month (median)ENSO-conditioned lean, wetENSO-conditioned lean, dry

Prime window: Jan–Feb — the deepest contiguous stretch of the conditioned season. Aim the trip there.

The analog poolEvery season since 1990 at Mammoth Mountain (ERA5, calibrated to the resort's reported average), colored by ENSO phase

375"775"1150"1525"1990-91: 241" (ONI +0.4)1991-92: 153" (ONI +1.7)1992-93: 437" (ONI +0.1)1993-94: 191" (ONI +0.1)1994-95: 502" (ONI +1.0)1995-96: 335" (ONI -0.9)1996-97: 343" (ONI -0.5)1997-98: 410" (ONI +2.2)1998-99: 305" (ONI -1.6)1999-00: 318" (ONI -1.7)2000-01: 211" (ONI -0.7)2001-02: 242" (ONI -0.1)2002-03: 273" (ONI +0.9)2003-04: 247" (ONI +0.4)2004-05: 389" (ONI +0.6)2005-06: 481" (ONI -0.8)2006-07: 166" (ONI +0.7)2007-08: 299" (ONI -1.6)2008-09: 255" (ONI -0.8)2009-10: 312" (ONI +1.5)2010-11: 488" (ONI -1.3)2011-12: 173" (ONI -0.7)2012-13: 183" (ONI -0.3)2013-14: 171" (ONI -0.3)2014-15: 112" (ONI +0.7)2015-16: 294" (ONI +2.6)2016-17: 1189" (ONI -0.2)2017-18: 569" (ONI -0.8)2018-19: 899" (ONI +0.9)2019-20: 400" (ONI +0.6)2020-21: 376" (ONI -0.9)2021-22: 474" (ONI -0.8)2022-23: 1414" (ONI -0.5)2023-24: 535" (ONI +1.9)2024-25: 530" (ONI -0.5)2025-26: 485" (ONI -0.4)19901995200020052010201520202025
La Niña winterNeutralEl Niño winterTypical winter (median)

Pass math for Mammoth Mountain

Verdicts run the full simulated snow distribution through breakeven math at ~$249/day window prices. Add trip legs on the home page to compare passes across your whole season.

10days
Best value for your plan
Ikon Base$1,019
STRONG BUY
100%seasons it pays off+$1,459expected vs tickets4.1breakeven days
  • Breakeven is 4.1 days at ~$249/day window tickets; you plan 10.
  • Covers Mammoth Mountain (unlimited).
  • Snow-adjusted across the simulated seasons, expect ~10.0 covered days; the pass beats window tickets in 100% of 10,000 simulated seasons (mean saving $1,459).
Unlimited at a smaller Alterra set and 5 days at most partners, with peak-holiday blackouts. Excludes Jackson Hole, Alta, Snowbasin, and Deer Valley.
Ikon Pass$1,449
STRONG BUY
100%seasons it pays off+$1,029expected vs tickets5.8breakeven days
  • Breakeven is 5.8 days at ~$249/day window tickets; you plan 10.
  • Covers Mammoth Mountain (unlimited).
  • Snow-adjusted across the simulated seasons, expect ~10.0 covered days; the pass beats window tickets in 100% of 10,000 simulated seasons (mean saving $1,029).
Unlimited at ~18 Alterra destinations, 7 days each at partners (Jackson Hole, Alta, Big Sky, Aspen...). No blackouts; some partners need reservations.

Mammoth Mountain 2026-27: straight answers

How much snow will Mammoth Mountain get in the 2026-27 season?
PassCast's latest 10,000-run simulation (reseeded 2026-07-10) puts the median at 346 inches — 106% of a typical season at Mammoth Mountain — with 80% of outcomes between 151 and 605 inches. The forecast blends Mammoth Mountain's own 36-season ENSO analog record with NOAA's seasonal outlook and the ECMWF SEAS5 ensemble.
Is a season pass worth it for Mammoth Mountain in 2026-27?
Mammoth Mountain is on Ikon Pass, Ikon Base for 2026-27. At roughly $249 for a peak-window day ticket, the Ikon Base ($1,019) breaks even in about 5 days here. PassCast's simulator on this page runs your planned days through all 10,000 simulated seasons for a full verdict.
When is the best time to ski Mammoth Mountain in 2026-27?
Jan–Feb is the prime window — the deepest contiguous stretch of the ENSO-conditioned season at Mammoth Mountain. Month-by-month medians are charted on this page.
How reliable will the snow be at Mammoth Mountain this season?
The simulation gives Mammoth Mountain a 55% chance of beating its typical season and a median of about 17 six-inch-plus powder days. Its skiability rating is 66/100 (“Deep & reliable”), updated daily.

Sources: ERA5 reanalysis & multi-model forecasts via Open-Meteo · NOAA CPC ONI, ENSO advisory & seasonal outlook · ECMWF SEAS5 · pass prices verified July 2026. See methodology for the honest fine print.