Atlas · Northern Rockies · ID
Sun Valley
9,150′ summit · 3,400′ vert · 2,154 acres · avg 220″/yr
Coin flip — Dec 16–31
Delivered 30″+ in 4 of the last 10 seasons
Over 20 winters: 6 of 20 · typical 22", most land 17"–31"
Before you book
This bet missed 6 of the last 10.
1 of the last 10 came in under 10″ — a bust, under a third of the bet.
Odds count natural snowfall only. At snowmaking-dependent resorts, early-season cover can be fine in a low-natural-snow year.
The season, window by window
The bet: 12″ of new snow per week, scaled to each window. Counted from real seasons — how our odds work.
Sun Valley · the shape of a typical winter
Typical new snow, window by window
The middle season — median new snow per window, counted from the last 20 winters. A picture of timing, not a forecast. Snow is streaky; hover any window for the usual range.
| Window | Bet | Delivered | Verdict | Typical | Biggest | Leanest |
|---|---|---|---|---|---|---|
| Nov 1–15 | 24″+ | 3 of 10 · 5 busts | Long shot | 9" | 35" 2022 | 0" 2019 |
| Nov 16–30 | 24″+ | 2 of 10 · 4 busts | Long shot | 14" | 38" 2012 | 1" 2008 |
| Dec 1–15 | 24″+ | 4 of 10 · 1 bust | Coin flip | 19" | 51" 2015 | 0" 2011 |
| Dec 16–31 | 30″+ | 4 of 10 · 1 bust | Coin flip | 22" | 84" 2025 | 3" 2013 |
| Jan 1–15 | 24″+ | 4 of 10 | Coin flip | 18" | 57" 2017 | 0" 2012 |
| Jan 16–31 | 30″+ | 0 of 10 · 4 busts | Long shot | 13" | 54" 2012 | 0" 2026 |
| Feb 1–15 | 24″+ | 4 of 10 · 3 busts | Coin flip | 10" | 80" 2019 | 1" 2011 |
| Feb 16–28/29 | 24″+ | 3 of 10 · 2 busts | Long shot | 17" | 68" 2017 | 3" 2015 |
| Mar 1–15 | 24″+ | 3 of 10 · 1 bust | Long shot | 17" | 68" 2023 | 1" 2015 |
| Mar 16–31 | 30″+ | 3 of 10 · 3 busts | Long shot | 19" | 54" 2011 | 0" 2022 |
| Apr 1–15 | 24″+ | 4 of 10 · 2 busts | Coin flip | 13" | 32" 2017 | 3" 2021 |
| Apr 16–30 | 24″+ | 0 of 10 · 2 busts | Long shot | 10" | 22" 2011 | 1" 2020 |
Biggest and leanest are the two ends of the same 20 winters Typical is counted from — the year is when it happened, most recent first where more than one season ties.
At the snow sensor
Reading the snow sensor…
Field notes
America's original destination resort — Baldy's long, continuous fall lines groomed to perfection, with the Warm Springs leg-burners as the signature. True expert terrain is limited, but the corduroy-and-consistency product is as good as it gets.
Ketchum is a real town with old-Hollywood bones. Snow totals run modest — this is Idaho's banana belt — and snowmaking plus grooming carry the product. It now sits on the Epic Pass.
Watch this window
We'll email you when Sun Valley's odds move on the Dec 16–31 window — and the quote gets recorded as it stands today, so we can be graded on it later.
Planning a whole season? See the season outlook.
These are historical odds from the last 20 winters — not a forecast. Inside 16 days of a trip, a forecast is the better instrument; beyond that, counting real seasons is the honest play. Every number on this page is quoted under methodology v1.2.0, the same math we grade ourselves against in public.