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Sun Valley weather in September 2025
Expect 20°C daytime maximum temperatures in the shade with on average 9 hours of sunshine per day in Sun Valley in September. Check more long-term weather averages for Sun Valley in September before you book your next holiday to Idaho in 2025/2026.
- 2020°C max day temperature
- 9 hours of sunshine per day
- 88 days with some rainfall
- 11°C min night temperature
- 1212 hours of daylight per day
- 0No heat & humidity
- 2626 mm of monthly rainfall
- 66 (High) UV index
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Sun Valley by month
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Recommended for Idaho
The September weather guide for Idaho (Sun Valley) shows long term weather averages processed from data supplied by CRU (University of East Anglia), the Met Office & the Netherlands Meteorological Institute. Find out more about our data sources.
Metric (°C / mm) | Imperial (°F / inches)
More about the USA
How hot is it in Sun Valley in September?
Daytime temperatures usually reach 20°C in Sun Valley in September, falling to 1°C at night.
How sunny is it in Sun Valley in September?
There are normally 9 hours of bright sunshine each day in Sun Valley in September - that's 73% of daylight hours.
Does it rain in Sun Valley in September?
There are usually 8 days with some rain in Sun Valley in September and the average monthly rainfall is 26mm.
Sun Valley September sunrise & sunset times
Browse the sunrise and sunset times for Sun Valley in September 2025. Select a month to view Sun Valley sunrise and sunset times for the next 12 months.
JanFebMarAprMayJunJulAugSepOctNovDec
Date | Sunrise times | Sunset times |
---|---|---|
Monday, 1st September 2025 | 06:01 | 19:12 |
Monday, 15th September 2025 | 06:17 | 18:47 |
Tuesday, 30th September 2025 | 06:34 | 18:19 |
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