Sun Valley weather in August
August in Sun Valley: warm, a little rain, with clean air — one of the weakest months to visit.
#11 of 12 months in Sun Valley · #601 of 604 destinations to visit in August · comfort 17/100 (tier F)
Updated June 2026 · climate normals from ERA5 reanalysis
Sun Valley climate normals — August
| Daytime high | 27°C / 80°F | 🌤 warm |
|---|---|---|
| Nighttime low | 12°C / 54°F | |
| Feels like (high) | 25°C / 77°F | |
| Rainfall | 39 mm / 1.5 in | 🌦 some rain |
| Rainy days | 7 days | |
| Humidity | 52% | 🍃 comfortable |
| Dew point | 8°C / 46°F | |
| Sunshine | 12.2 h/day | |
| Daylight | 13.9 h | |
| Wind | 14 km/h / 9 mph | |
| Air quality (US AQI) | 46 | 🍃 good |
Monthly averages from ERA5 reanalysis. AQI is the mean US Air Quality Index for the month.
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Sun Valley in August — FAQ
- Is August a good time to visit Sun Valley?
- August in Sun Valley: warm, a little rain, with clean air — one of the weakest months to visit. It ranks #11 of 12 months for Sun Valley on SeasonMap's comfort score (17/100).
- What is the weather like in Sun Valley in August?
- In August, Sun Valley averages a daily high of 26.5°C and a low of 12°C, with about 38.5 mm of rain over roughly 7 rainy days.
- What is the air quality in Sun Valley in August?
- Sun Valley has a mean US Air Quality Index of about 46 in August.