What is the weather like in Boise vs Yellowstone National Park in September?

In September, Boise averages 27°C high / 12°C low with about 8 mm of rain; Yellowstone National Park averages 17°C high / 1°C low with about 59 mm.

Boise vs Yellowstone National Park in September

Boise is the better pick in September — 94 vs 84 on SeasonMap's comfort score. Boise is warm, dry, clean air, while Yellowstone National Park is cool, a little rain, clean air.

Boise vs Yellowstone National Park — September climate, side by side

	🇺🇸 Boise	🇺🇸 Yellowstone National Park
Comfort score	94/100 (S)	84/100 (A)
Feels-like high	25°C	14°C
Avg high / low	27° / 12°	17° / 1°
Rainfall	8 mm	59 mm
Rainy days	3	11
Humidity	41%	59%
Air quality (AQI)	40	43

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

Month by month

Boise vs Yellowstone National Park in September — FAQ

Is September better in Boise or Yellowstone National Park?: Boise is the better pick in September — 94 vs 84 on SeasonMap's comfort score. Boise is warm, dry, clean air, while Yellowstone National Park is cool, a little rain, clean air.
What is the weather like in Boise vs Yellowstone National Park in September?: In September, Boise averages 27°C high / 12°C low with about 8 mm of rain; Yellowstone National Park averages 17°C high / 1°C low with about 59 mm.