Transit Desk

Climate

Weather in United States in September

Weather in United States, September
In September, United States sees average highs of 26.1°C (79°F) and lows of 16.8°C (62°F), with around 116 mm of rain. It is one of the best months to visit.

United States — September

United States September
Daytime high
26.1°C (79°F)
Overnight low
16.8°C (62°F)
Rainfall
116 mm
Best-time rank
Recommended month

How September compares

United States, September vs. the annual average (2025)
This month26.1°C (79°F) / 16.8°C (62°F) · 116 mm
Yearly average19.5°C (67°F) / 9.7°C (49°F) · 108 mm

September in United States runs 6.6°C (11.9°F) warmer than the yearly average, and is wetter than the yearly average. Pack layers you can adjust through the day — mild conditions, and something waterproof — this is a wetter month.

Common questions

What is the weather like in United States in September?

Average highs of 26.1°C (79°F) and lows of 16.8°C (62°F), with around 116 mm of rain.

Is September a good time to visit United States?

Yes — September is one of the more comfortable months in United States, based on temperature and rainfall.

Updated climate normals, 2025