What is the weather like in Gateway Arch National Park vs Indianapolis in September?

In September, Gateway Arch National Park averages 29°C high / 15°C low with about 89 mm of rain; Indianapolis averages 27°C high / 16°C low with about 64 mm.

Gateway Arch National Park vs Indianapolis in September

Indianapolis is the better pick in September — 89 vs 81 on SeasonMap's comfort score. Indianapolis is warm, a little rain, clean air, while Gateway Arch National Park is hot, rainy, clean air.

Gateway Arch National Park vs Indianapolis — September climate, side by side

	🇺🇸 Gateway Arch National Park	🇺🇸 Indianapolis
Comfort score	81/100 (A)	89/100 (A)
Feels-like high	30°C	28°C
Avg high / low	29° / 15°	27° / 16°
Rainfall	89 mm	64 mm
Rainy days	5	5
Humidity	67%	68%
Air quality (AQI)	50	42

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

Month by month

Gateway Arch National Park vs Indianapolis in September — FAQ

Is September better in Gateway Arch National Park or Indianapolis?: Indianapolis is the better pick in September — 89 vs 81 on SeasonMap's comfort score. Indianapolis is warm, a little rain, clean air, while Gateway Arch National Park is hot, rainy, clean air.
What is the weather like in Gateway Arch National Park vs Indianapolis in September?: In September, Gateway Arch National Park averages 29°C high / 15°C low with about 89 mm of rain; Indianapolis averages 27°C high / 16°C low with about 64 mm.