Sun Valley (Ketchum), Idaho weather in August
Temperature, rain and sunshine in August: long-term averages from 30 years of weather data, not a forecast.
Holiday weather in August
Excellent
Best time to visit: June, August – September
Best for skiing: December – April
What is the weather like in Sun Valley (Ketchum), Idaho in August?
In August, Sun Valley (Ketchum), Idaho is warm: daytime highs average 26 °C, and nights cool down to about 11 °C. With around 10 hours of sunshine a day, there is plenty of sun. Rain is rare: about 3 days bring 12 mm in total. All in all, August is an excellent month for a holiday in Sun Valley (Ketchum), Idaho.
August compared
How the weather changes from July to September. Tap a month to open it.
| JulyJul | AugustAug | SeptemberSep | |
|---|---|---|---|
| Score | 81 | 90 | 97 |
| Day | 28° | 26° | 21° |
| Night | 12° | 11° | 7° |
| Sun | 11 h | 10 h | 8 h |
| Rain days | 3 | 3 | 4 |
More details for August
- Daylight
- 14 h 3 min06:41 – 20:44
- UV index
- 9 · very highclear sky, noon (estimate)All months
- Muggy days
- 0 daysdew point 18 °C or moreAll months
- Wind
- 15 km/haverage daily peakAll months
- Cloud cover
- 26 %on averageAll months
- Hot days
- 4 days30 °C or moreAll months
- Snow days
- 0 days1 cm or more of fresh snowAll months
- Time zone
- UTC−6America/Boise
How the score comes together
- Temperatureweight 50 %80 %
- Sunshineweight 20 %100 %
- Few rainy daysweight 30 %100 %
Each factor is rated from 0 to 100 % and weighted for the travel style “Mountain air”.
What to pack in August
- Sunscreen
- Sunglasses & sun hat
- Light, breathable clothes
- A jumper for the evenings
Sun Valley (Ketchum), Idaho in August: quick answers
Is Sun Valley (Ketchum), Idaho hot in August?
Warm rather than hot: in August, daytime highs in Sun Valley (Ketchum), Idaho average 26 °C and nights cool to about 11 °C. On about 4 days the thermometer climbs to 30 °C or more.
Does it rain much in Sun Valley (Ketchum), Idaho in August?
Rain is rare: about 3 days bring 12 mm in total.
Sun Valley (Ketchum), Idaho month by month
The whole year in Sun Valley (Ketchum), IdahoAll destinations: USAWhere to go in August
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