Mountains / Northern Rockies

Sun Valley ID

5,7519,150 ft · long-term average 200" per season · window ticket ~$265 · prime window Dec–Jan

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

The short answer: PassCast projects a median of 170" at Sun Valley for 2026-2790% of a typical season — with a skiability rating of 42/100, ~6 powder days, and Dec–Jan as the prime window. Updated daily from 10,000 simulations.

42SKIABILITY / 100Selective — time it well
Snow quantity 35%49
Season lean 30%38
Powder days 20%24
Bust risk 15%59
Median sim
170" (90% of typical)
P(above typical)
38%
Powder days
~6 (6"+ days)

80% of simulated seasons land between 114" and 260". 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 Sun Valley, tilted by the live seasonal outlook

100"150"200"250"300"350"400"P10 114"P50 170"P90 260"typical 189"

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 Sun Valley'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: unfavorable (moderate-strong)

Jackson Hole and Big Sky are La Niña-favored (seasonal MEI correlation ~-47%); El Niño winters trend warmer with below-normal precipitation. Applied as a -5% 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 readNorthern Rockies · from the 2026-27 outlook

Jackson, Big Sky, and the Idaho panhandle are La Niña country, and a strong El Niño typically strands them on the dry, warm side of a southward-displaced storm track — strong La Niña months out-snow strong El Niño months by 30% or more at inland areas. 1997-98 and 2023-24 both brought below-average, late-starting seasons here. Plan on 80-90% of normal snowfall, cold enough at elevation to preserve quality, with the best stretch arriving February onward.

Full global outlook →

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

Nov87%Dec84%Jan105%Feb100%Mar100%Apr100%
Typical month (median)ENSO-conditioned lean, wetENSO-conditioned lean, dry

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

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

100"175"275"350"1990-91: 147" (ONI +0.4)1991-92: 116" (ONI +1.7)1992-93: 244" (ONI +0.1)1993-94: 127" (ONI +0.1)1994-95: 297" (ONI +1.0)1995-96: 272" (ONI -0.9)1996-97: 314" (ONI -0.5)1997-98: 185" (ONI +2.2)1998-99: 291" (ONI -1.6)1999-00: 174" (ONI -1.7)2000-01: 108" (ONI -0.7)2001-02: 183" (ONI -0.1)2002-03: 206" (ONI +0.9)2003-04: 173" (ONI +0.4)2004-05: 149" (ONI +0.6)2005-06: 326" (ONI -0.8)2006-07: 186" (ONI +0.7)2007-08: 197" (ONI -1.6)2008-09: 205" (ONI -0.8)2009-10: 136" (ONI +1.5)2010-11: 258" (ONI -1.3)2011-12: 221" (ONI -0.7)2012-13: 174" (ONI -0.3)2013-14: 191" (ONI -0.3)2014-15: 143" (ONI +0.7)2015-16: 233" (ONI +2.6)2016-17: 290" (ONI -0.2)2017-18: 169" (ONI -0.8)2018-19: 249" (ONI +0.9)2019-20: 128" (ONI +0.6)2020-21: 150" (ONI -0.9)2021-22: 139" (ONI -0.8)2022-23: 268" (ONI -0.5)2023-24: 191" (ONI +1.9)2024-25: 204" (ONI -0.5)2025-26: 156" (ONI -0.4)19901995200020052010201520202025
La Niña winterNeutralEl Niño winterTypical winter (median)

Pass math for Sun Valley

Verdicts run the full simulated snow distribution through breakeven math at ~$265/day window prices. Add trip legs on the home page to compare passes across your whole season.

10days
Best value for your plan
Mountain Collective$699
STRONG BUY
100%seasons it pays off+$845expected vs tickets3.3breakeven days
  • Breakeven is 3.3 days at ~$265/day window tickets; you plan 10.
  • Covers Sun Valley (2d +50% off after).
  • Snow-adjusted across the simulated seasons, expect ~9.7 covered days; the pass beats window tickets in 100% of 10,000 simulated seasons (mean saving $845).
2 days at each of 27 destinations plus 50% off additional days. No blackouts; some resorts require reservations.
Ikon Pass$1,449
STRONG BUY
100%seasons it pays off+$406expected vs tickets5.5breakeven days
  • Breakeven is 5.5 days at ~$265/day window tickets; you plan 10.
  • Covers Sun Valley (7d).
  • Snow-adjusted across the simulated seasons, expect ~9.7 covered days; the pass beats window tickets in 100% of 10,000 simulated seasons (mean saving $406).
Unlimited at ~18 Alterra destinations, 7 days each at partners (Jackson Hole, Alta, Big Sky, Aspen...). No blackouts; some partners need reservations.

Sun Valley 2026-27: straight answers

How much snow will Sun Valley get in the 2026-27 season?
PassCast's latest 10,000-run simulation (reseeded 2026-07-10) puts the median at 170 inches — 90% of a typical season at Sun Valley — with 80% of outcomes between 114 and 260 inches. The forecast blends Sun Valley's own 36-season ENSO analog record with NOAA's seasonal outlook and the ECMWF SEAS5 ensemble.
Is a season pass worth it for Sun Valley in 2026-27?
Sun Valley is on Ikon Pass, Mountain Collective for 2026-27. At roughly $265 for a peak-window day ticket, the Mountain Collective ($699) breaks even in about 4 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 Sun Valley in 2026-27?
Dec–Jan is the prime window — the deepest contiguous stretch of the ENSO-conditioned season at Sun Valley. Month-by-month medians are charted on this page.
How reliable will the snow be at Sun Valley this season?
The simulation gives Sun Valley a 38% chance of beating its typical season and a median of about 6 six-inch-plus powder days. Its skiability rating is 42/100 (“Selective — time it well”), 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.