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Mammoth Mountain ski resort
Ikon PassView resorts
Tier C — ENSO-proof

North America

Mammoth Mountain Snow Forecast

Closed for the season

Best months to book: February, January, March · last season + 30-yr record

Closed for the season — closed June 7

Weather data is still collected for informational purposes.

Last Snowfall

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Past 24 Hours

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7-Day Forecast

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Snow Depth

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Updated: Sep 20, 11:00 PM•Weather at base: 2,424m
SnowSure™ Score2025-26 season
Closed for the season

Mammoth Mountain is closed for the season. Here is when it is usually best to book.

Best months to book: February, January, March. Best weeks: 20 Mar–25 Mar, 27 Mar–2 Apr, 10 Apr–16 Apr.NovDec2Jan1Feb3MarAprMayOpens 14 Nov

February

#1 to book

88cm avg

January

#2 to book

87cm avg

March

#3 to book

73cm avg · scored 14.3

Best weeks to book

  1. #120 Mar – 25 Marscored 14
  2. #227 Mar – 2 Aprscored 18.4
  3. #310 Apr – 16 Aprscored 34.4

Ranked on 25% last season's SnowSure score (2025-26) · 75% 30-year snowfall and base-depth record. The live score returns when the lifts turn.

Snow Summary

3,369m
ECMWFGFSGEMJMAICONMétéo-Fr

Updated Sep 20, 2026 at 11:00 PM

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24h
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Past 10d
7-Day Forecast
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Now20
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S26
Days 8–14 and every model are in Pro.Unlock with Pro
Past
Today
Forecast

Hourly Forecast

20 Sun
13° / 1°
21 Mon
10° / 1°
22 Tue
12° / -0°
23 Wed
15° / 2°
24 Thu
13° / 3°
25 Fri
11° / 1°
26 Sat
11° / 0°
Days 8–14 and every model are in SnowSure Pro.Unlock with Pro
AMPMNightAMPMNightAMPMNightAMPMNightAMPMNightAMPMNightAMPMNight27 Sun28 Mon29 Tue30 Wed1 Thu2 Fri3 Sat
Conditions☁️⛅☁️☁️❄️☀️☀️☀️☀️☀️☀️☀️☀️☀️☀️🌤️🌧️☀️☀️☀️☀️
cloudysome cloudscloudycloudysnowclearclearclearclearclearclearclearclearclearclearmostly clearlight drizzleclearclearclearclear
Summit3,369 mModeled
Temp°C7°12°4°6°4°2°6°11°2°8°14°4°8°12°5°6°10°3°6°10°3°
Feels like°C3°8°0°2°1°-2°2°7°-1°5°11°1°5°8°1°2°4°-1°1°6°-1°
Snowcm····1.5················
Precipmm····6.3···········0.6····
Windkm/h6106875711629351631223710177
Mid-mountain2,897 mModeled
Temp°C7°17°6°8°14°5°7°16°6°9°19°6°9°18°6°9°15°5°9°15°5°
Feels like°C4°13°2°4°10°2°4°12°2°5°15°3°6°14°3°4°10°2°5°10°1°
Snowcm·····················
Precipmm····0.3················
Windkm/h4945104512449541251321713199
Base2,424 mModeled
Temp°C10°20°9°11°17°9°10°19°9°12°22°10°12°21°9°12°18°9°12°18°8°
Feels like°C7°16°6°8°14°6°7°15°6°9°19°7°10°18°6°8°13°5°8°13°5°
Snowcm·····················
Precipmm····0.3················
Windkm/h4945104512449541251321713199
Humidity%371438392052501953371550492057382751361654
0°C linem—————————————————————
Forecast Range · SnowSure Pro

Every model for Mammoth Mountain, side by side for 14 days

Where the models agree, where they split, and which one has been most accurate here. Free for 14 days, then yearly.

Unlock with Pro

SnowSure™ blend — verified model weighting

The black line is not a simple average. For Mammoth Mountain (sierra), we combine seven global weather models using weights learned from daily forecast verification — comparing each model's prediction to measured snowfall (SNOTEL, resort reports, ERA5).

  • 1.Horizon buckets: days 1–3, 4–7, and 8–14 each get separate weights — short-range skill differs from long-range.
  • 2.Regional calibration: weights come from verified error in this geography (Rockies, Alps, Japan, etc.), recalculated weekly.
  • 3.Ground truth only: we never grade a forecast against another model — only against measured snow.

Building verification history for this resort.

How we verify forecasts →

Snowfall Forecast Maps

California & Sierra Nevada region

El Niño Outlook · Winter 2026-27

Mammoth Mountain El Niño rank & forecast

Mammoth Mountain ranks #249 of 488 SnowSure resorts — Tier C, −3% in strong El Niño winters.

Tier C — ENSO-proof: Strong El Niño winters looked like a normal year here — within about ±3% of this resort’s own 30-year snowfall average. Not a jackpot, not a bust: a hedge if you’re planning around El Niño.

#249 of 488Tier C — ENSO-proof

Strong-event signal: −3% vs this resort's 30-yr avg

In the three strongest El Niño winters on record ('97-98, '15-16, '23-24), Mammoth Mountain averaged -3% versus its own 30-year snowfall baseline — effectively ENSO-proof. Mammoth Mountain has held within a few percent of normal across every phase of the Pacific cycle, making it one of the safest bets of a record El Niño winter 2026-27. Analog winters: '97-98 -4%, '15-16 -32%, '23-24 +27%.

'97-98 −4%'15-16 −32%'23-24 +27%

Signal = average snowfall in the three strongest El Niño winters since 1996 ('97-98, '15-16, '23-24) vs this resort's own 30-year ERA5 baseline. n=3 — a lean, not a law. Updated monthly against measured snowfall Dec–Mar.

Full El Niño report →

ENSO seasonal analog

History · not a forecast

In 10 past El Niño winters at Mammoth Mountain, ERA5 season snowfall median was 380 cm (150 in), about 6% above this resort’s long-term median. This is a historical analog from reanalysis — not a prediction of this winter’s storm track.

Prevailing ONI

El Niño

JJA 2026 · ANOM +1.8°C

Analog season median

380cm

10 El Niño winters · 6% above median

All-season median

360cm

Across 30 ERA5 seasons (2026-27)

PhaseSeasonsMedianp25–p75Recent analogs
El Niñocurrent10380cm284cm – 452cm2023, 2019, 2018, 2015, 2014, 2009
La Niña12355cm297cm – 524cm2022, 2021, 2020, 2017, 2011, 2010
ENSO-neutral8306cm227cm – 526cm2025, 2024, 2016, 2013, 2012, 2003

Season snowfall from Open-Meteo ERA5 reanalysis (~9 km). ENSO phase from NOAA CPC Oceanic Niño Index. Relative phase differences are more trustworthy than absolute cm totals. Source: NOAA CPC Oceanic Niño Index + Open-Meteo ERA5 via SnowSure season archive.

Local Reports

0 reports

How accurate is this forecast?

We verify every forecast against what actually fell — see the model-by-model results.

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Frequently asked questions about Mammoth Mountain

How much snow is Mammoth Mountain getting this week?
No significant snow is forecast at Mammoth Mountain over the next 7 days.
What is the 14-day snow forecast for Mammoth Mountain?
The full 14-day forecast for Mammoth Mountain — the SnowSure™ blend and every model we track, day by day — is part of SnowSure Pro. The first 7 days are free on this page.
How accurate are SnowSure forecasts for Mammoth Mountain?
We verify every forecast against what actually fell and publish the results — see our forecast verification pages for model-by-model accuracy, updated continuously.