Sun Valley (Ketchum), Idaho weather in December
Temperature, rain and sunshine in December: long-term averages from 30 years of weather data, not a forecast.
Holiday weather in December
Poor
Best time to visit: June, August – September
Best for skiing: December – April
What is the weather like in Sun Valley (Ketchum), Idaho in December?
In December, Sun Valley (Ketchum), Idaho is freezing cold: daytime highs average −2 °C, and nights often drop below freezing (−14 °C). Expect around 4 hours of sunshine a day. Precipitation, often as snow, falls on about 10 days, totalling 70 mm. Snow falls on about 9 days. All in all, December is not an ideal month for a holiday in Sun Valley (Ketchum), Idaho.
December compared
How the weather changes from November to January. Tap a month to open it.
| NovemberNov | DecemberDec | JanuaryJan | |
|---|---|---|---|
| Score | 30 | 21 | 25 |
| Day | 4° | −2° | −3° |
| Night | −8° | −14° | −14° |
| Sun | 5 h | 4 h | 5 h |
| Rain days | 7 | 10 | 9 |
More details for December
- Daylight
- 8 h 57 min08:04 – 17:01
- UV index
- 1 · lowclear sky, noon (estimate)All months
- Muggy days
- 0 daysdew point 18 °C or moreAll months
- Wind
- 10 km/haverage daily peakAll months
- Cloud cover
- 60 %on averageAll months
- Hot days
- 0 days30 °C or moreAll months
- Snow days
- 9 days1 cm or more of fresh snowAll months
- Time zone
- UTC−7America/Boise
How the score comes together
- Temperatureweight 50 %0 %
- Sunshineweight 20 %18 %
- Few rainy daysweight 30 %58 %
Each factor is rated from 0 to 100 % and weighted for the travel style “Mountain air”.
What to pack in December
- Warm jacket
- Hat, scarf & gloves
- Rain jacket or umbrella
Sun Valley (Ketchum), Idaho in December: quick answers
Is Sun Valley (Ketchum), Idaho hot in December?
No. In December, Sun Valley (Ketchum), Idaho is freezing cold: daytime highs average −2 °C and nights drop to about −14 °C.
Does it rain much in Sun Valley (Ketchum), Idaho in December?
Rain is frequent, with about 10 rainy days and 70 mm in total.
Sun Valley (Ketchum), Idaho month by month
The whole year in Sun Valley (Ketchum), IdahoAll destinations: USAWhere to go in December
Climate averages 1996–2025, not a forecast. Data: Copernicus ERA5 / ERA5-Land via Open-Meteo.com (CC BY 4.0), NOAA OISST, WMO 1991–2020 (NOAA NCEI), GeoNames (CC BY 4.0). Sources & licences