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Keystone ski resort
Epic PassView resorts
Tier C — ENSO-proof

North America

Keystone Snow Forecast

Last Snowfall

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Past 24 Hours

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Past 48 Hours

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7-Day Forecast

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Snow Depth

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Updated: Sep 20, 5:00 PM•Weather at base: 2,830m
SnowSure™ Score2025-26 season
Pre-season — not open yet

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

Best months to book: April, March, February. Best weeks: 5 Apr–11 Apr, 29 Mar–4 Apr, 1 Mar–7 Mar.NovDecJan3Feb2Mar1AprCloses 12 Apr

April

#1 to book

51cm avg · scored 24.8

March

#2 to book

41cm avg · scored 25.9

February

#3 to book

36cm avg · scored 32.4

Best weeks to book

  1. #15 Apr – 11 Aprscored 23.4
  2. #229 Mar – 4 Aprscored 25
  3. #31 Mar – 7 Marscored 31

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

3,782m
ECMWFGFSGEMJMAICONMétéo-Fr

Updated Sep 20, 2026 at 5:00 PM

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24h
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Past 10d
7-Day Forecast
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Now20
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M21
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T22
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W23
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F25
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S26
Days 8–14 and every model are in Pro.Unlock with Pro
Past
Today
Forecast

Hourly Forecast

20 Sun
9° / -3°
21 Mon
10° / -4°
22 Tue
11° / -2°
23 Wed
9° / -2°
24 Thu
8° / -2°
25 Fri
10° / -3°
26 Sat
11° / -4°
Days 8–14 and every model are in SnowSure Pro.Unlock with Pro
AMPMNightAMPMNightAMPMNightAMPMNightAMPMNightAMPMNightAMPMNight27 Sun28 Mon29 Tue30 Wed1 Thu2 Fri3 Sat
Conditions☀️☀️☀️🌤️⛅☀️🌤️🌧️⛅☁️☁️☁️☁️🌧️☁️⛅🌤️☀️☀️🌧️☀️
clearclearclearmostly clearsome cloudsclearmostly clearlight drizzlesome cloudscloudycloudycloudycloudylight drizzlecloudysome cloudsmostly clearclearclearlight drizzleclear
Summit3,782 mModeled
Temp°C2°8°-1°1°10°0°4°9°1°3°8°1°3°7°0°1°9°0°2°11°1°
Feels like°C-1°3°-4°-2°5°-4°1°7°-3°0°4°-2°0°3°-2°-2°5°-3°-1°8°-2°
Snowcm·····················
Precipmm·······1.10.4·0.3··0.90.6·0.20.1·0.50.1
Windkm/h71953134446510361135156462
Mid-mountain3,306 mModeled
Temp°C5°11°3°5°13°3°7°13°4°6°11°4°6°10°3°4°12°3°5°14°4°
Feels like°C2°6°-1°2°9°-1°4°10°1°3°8°2°4°6°1°2°8°0°2°11°1°
Snowcm·····················
Precipmm·······1.10.4·0.3··0.90.6·0.20.1·0.50.1
Windkm/h71953134446510361135156462
Base2,830 mModeled
Temp°C8°14°6°8°16°6°10°16°7°9°15°7°9°13°7°7°15°6°8°17°7°
Feels like°C6°10°3°5°12°3°8°14°5°7°11°5°7°10°5°6°12°4°6°15°5°
Snowcm·····················
Precipmm·······1.10.4·0.3··0.90.6·0.20.1·0.50.1
Windkm/h71953134446510361135156462
Humidity%643266552458724285754578716187863888622868
0°C linem—————————————————————
Forecast Range · SnowSure Pro

Every model for Keystone, 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 Keystone (rockies), 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

Rockies & Southwest region

El Niño Outlook · Winter 2026-27

Keystone El Niño rank & forecast

Keystone ranks #208 of 488 SnowSure resorts — Tier C, 0% 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.

#208 of 488Tier C — ENSO-proof

Strong-event signal: 0% vs this resort's 30-yr avg

In the three strongest El Niño winters on record ('97-98, '15-16, '23-24), Keystone averaged +0% versus its own 30-year snowfall baseline — effectively ENSO-proof. Keystone 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 -17%, '15-16 +2%, '23-24 +16%.

'97-98 −17%'15-16 +2%'23-24 +16%

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 Keystone, ERA5 season snowfall median was 305 cm (120 in), about 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

305cm

10 El Niño winters · ≈ long-term median

All-season median

305cm

Across 30 ERA5 seasons (2026-27)

PhaseSeasonsMedianp25–p75Recent analogs
El Niñocurrent10305cm298cm – 333cm2023, 2019, 2018, 2015, 2014, 2009
La Niña12306cm264cm – 318cm2022, 2021, 2020, 2017, 2011, 2010
ENSO-neutral8293cm265cm – 331cm2025, 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.

→

Frequently asked questions about Keystone

How much snow is Keystone getting this week?
No significant snow is forecast at Keystone over the next 7 days.
What is the 14-day snow forecast for Keystone?
The full 14-day forecast for Keystone — 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 Keystone?
We verify every forecast against what actually fell and publish the results — see our forecast verification pages for model-by-model accuracy, updated continuously.