Sun Valley Snow Conditions Overview
Sun Valley in Idaho, USA sits at 2,789m (9,151ft) elevation and averages 246cm of annual snowfall based on 10 years of historical data (2015-2025). During the ski season, Sun Valley receives approximately 220cm of snow. The best month for powder is February, averaging 48.4cm of snowfall with a 25% powder probability. The highest chance of fresh powder (15cm+ in any given week) occurs in December and February at 27%.
- Annual Snowfall
- 246cm
- Elevation
- 2,789m
- Best Month
- February
- Powder Probability
- 27%
Snowfall data sourced from ERA5 reanalysis via Open-Meteo Historical Weather API (2015-2025).
Check Sun Valley snow forecast for your dates
Based on 10 years of historical snowfall data
About Sun Valley
Sun Valley Resort in Idaho's Sawtooth Range, opened in 1936 by Union Pacific Railroad chairman Averell Harriman, is widely credited as the first destination ski resort in the United States — the world's first chairlift was installed here that same year on Proctor Mountain. Lift-served terrain spans Bald Mountain ("Baldy") to a summit of 2,789m (9,150ft) above the towns of Ketchum and Sun Valley village near 1,750m, with the gentler Dollar Mountain across the valley for beginners. Its position east of the Sawtooth crest in the Big Wood River valley shelters it from the heaviest Pacific moisture, producing a continental snow climate with lighter, drier snow than Sierra resorts at a similar latitude. Across 10 winters of ERA5 reanalysis data (2015-2025), Sun Valley averages roughly 246cm (97 inches) of snowfall a year, with the heaviest accumulations concentrated between December and March. This page uses that decade of historical snowfall data to help you find the weeks most likely to deliver fresh powder.
Snowfall patterns over the last decade
Across ERA5 reanalysis snowfall records from 2015 to 2025, Sun Valley averages 246cm (97 inches) of snowfall a year, with the November-through-April ski season delivering about 220cm of that total. February is the heaviest calendar month in the 10-year average at 48.4cm, narrowly ahead of December at 44.0cm, March at 43.2cm and January at 40.5cm — four closely-matched midwinter months. November contributes 24.5cm to build the base and April tails off sharply at 19.0cm. Ranked by powder probability — the share of weeks with at least 15cm of fresh snow — December leads at 27%, then February at 25%, January at 24% and March at 20%, with November at 15% and April collapsing to 3%. The window with both the deepest totals and the best powder odds is mid-December through mid-March; April trips at Sun Valley face a steep drop in fresh-snow frequency.
Year-to-year variability at Sun Valley is heavily skewed to February. February snowfall in the 10-year record ranges from just 6.5cm in the driest winter to 139.9cm in the wettest — a 22-fold spread that is among the widest February ranges of any North American resort tracked here. March is also volatile, swinging between 13.2cm and 106.4cm (an eight-fold range), while January sits in a much tighter band of 21.8cm to 83.7cm — every January in the decade cleared 21cm. December ranges from 11.4cm to 71.5cm, and April collapses to a 9.8cm to 30.9cm window with powder probability already in the single digits. The relatively narrow January range is the planning sweet spot: no January in the record produced a thin month, while the wettest delivered roughly double the average.
In context, Sun Valley's 246cm annual average is modest compared to the Sierra Nevada and Pacific Northwest resorts tracked here — Palisades Tahoe averages 662cm, Mammoth 695cm and Whistler 969cm — but it is closer to the lighter, drier snow climates of the Rocky Mountain interior. The position east of the Sawtooth crest in Idaho's Big Wood River valley shelters Sun Valley from the heaviest Pacific moisture, producing colder, lower-density snow than the Sierra resorts at the same latitude. The 2,789m summit on Bald Mountain and roughly 1,000m of vertical preserve snow quality well into March, but April's 19.0cm average and 3% powder probability mean late-season trips here are driven more by sunshine and groomed conditions than fresh powder. For peak powder probability the mid-December through mid-March window concentrates the highest hit rate; February has historically delivered the deepest single-month totals in the record, while January is the most reliable month season-to-season.
Snow & Weather Conditions
We use 10 years of historical data to help you plan — not a live snow report.
Central Idaho receives a mix of Pacific moisture and cold continental air, producing reliable snowfall with good powder quality. The high elevation ensures a cold, consistent climate that favours natural snow preservation. Storms frequently deliver generous totals, and the altitude keeps the snowpack dense and skiable throughout the core winter months. Season-long totals generally land between 6 and 10 metres, translating to a robust mid-winter base well above 2 metres.
Best Time to Ski
The best time to ski at Sun Valley is December and February, with 44cm average snowfall and 27% powder probability. Based on 10 years of historical snowfall data from PowderDays. Season runs late November to mid-April. January and February offer the most reliable conditions. Browse PowderDays' decade-spanning snow statistics to pinpoint the weeks with the heaviest accumulations.
Powder Probability by Month
Chance of 15cm+ fresh snow in any given week (10 years of data):
- Nov15%
- Dec27%
- Jan24%
- Feb25%
- Mar20%
- Apr3%
10-Year Snow History
| Month | Avg Snowfall (cm) | Record High | Record Low | Powder Probability |
|---|---|---|---|---|
| Nov | 24.5 | 48.9 | 6.6 | 15% |
| Dec | 44.0 | 71.5 | 11.4 | 27% |
| Jan | 40.5 | 83.7 | 21.8 | 24% |
| Feb | 48.4 | 139.9 | 6.5 | 25% |
| Mar | 43.2 | 106.4 | 13.2 | 20% |
| Apr | 19.0 | 30.9 | 9.8 | 3% |
What Makes It Special
Long, sweeping groomers and open bowls with impressive vertical on a relatively uncrowded mountain. A classic, understated American ski-town feel with historic roots dating back to the 1930s. Sun Valley pioneered the chairlift.
Sun Valley, Idaho installed the world's first chairlift in 1936, adapted from a banana-loading conveyor system designed by Union Pacific Railroad engineers. This innovation transformed skiing from a backcountry pursuit into a modern recreational sport.
Data Sources & Methodology
All snowfall statistics for Sun Valley are based on 10 years of historical data (2015-2025) from the Open-Meteo Historical Weather API, which provides ERA5 reanalysis data from the European Centre for Medium-Range Weather Forecasts (ECMWF). Daily snowfall totals are queried at Sun Valley's coordinates (43.70, -114.35) and 2,789m elevation, then aggregated into monthly averages, record highs/lows, and powder probability scores. Powder probability represents the chance of receiving 15cm or more of fresh snow in any given week during that month.