Dayton Weather in September

The climate in Dayton during September can be summarized as warm and reasonably dry.

September is in the fall / autumn in Dayton and is typically the 4th warmest month of the year. Daytime maximum temperatures average around 25°C (77°F), whilst at night 13°C (55°F) is normal.

On average September is the 4th driest month of the year in Dayton with around 67mm 2.6 inches of rain making it a reasonably dry time to visit. This rainfall is typically spread over 8 days, although this may vary considerably.

On the flip side this corresponds to an average of 8.5 hours of sunshine per day.

The data used in these monthly averages covers a period of over 100 years right up until last year. As such they are a valid prediction of what to expect for the weather in Dayton in September 2025.