What is the weather like in Alta vs Sun Valley in September?

In September, Alta averages 17°C high / 8°C low with about 97 mm of rain; Sun Valley averages 22°C high / 3°C low with about 30 mm.

Alta vs Sun Valley in September

Alta is the better pick in September — 22 vs 18 on SeasonMap's comfort score. Alta is nice, rainy, clean air, while Sun Valley is nice, dry, clean air.

Alta vs Sun Valley — September climate, side by side

	🇺🇸 Alta	🇺🇸 Sun Valley
Comfort score	22/100 (F)	18/100 (F)
Feels-like high	17°C	19°C
Avg high / low	17° / 8°	22° / 3°
Rainfall	97 mm	30 mm
Rainy days	12	5
Humidity	52%	52%
Air quality (AQI)	42	40

Monthly climate normals (ERA5 reanalysis). Comfort scores are SeasonMap estimates.

Month by month

Alta 🇺🇸 United Statesnice, rainy, clean air · best March22
Sun Valley 🇺🇸 United Statesnice, dry, clean air · best February18

Alta vs Sun Valley in September — FAQ

Is September better in Alta or Sun Valley?: Alta is the better pick in September — 22 vs 18 on SeasonMap's comfort score. Alta is nice, rainy, clean air, while Sun Valley is nice, dry, clean air.
What is the weather like in Alta vs Sun Valley in September?: In September, Alta averages 17°C high / 8°C low with about 97 mm of rain; Sun Valley averages 22°C high / 3°C low with about 30 mm.