Dayton Weather in September

What's the weather like in Dayton (Washington) in September 2025?

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

September is in the fall / autumn in Dayton and is typically the 4th warmest month of the year. Daytime maximum temperatures average around 23°C (73°F), whilst at night 7°C (44°F) is normal.

Dayton weather averages (imperial / metric)
Daytime temperature 23°C 73.3°F
Nightly temperature 6.7°C 44°F
Average temperature 14.8°C 58.6°F
Daily sunshine 9.8 hrs
Avg rainfall 25 mm 1 ins
Rainy days 6 days
Sea temperature 13.2°C 55.8°F
Humidity 50%
Windspeed 13.7kph 9 mph

On average September is the 3rd driest month of the year in Dayton with around 25mm 1 inches of rain making it a dry time to visit. This rainfall is typically spread over 6 days, although this may vary considerably.

On the flip side this corresponds to an average of 9.8 hours of sunshine per day.

September temperatures in Dayton

Dayton average temperature in September

September rainfall

Dayton average rain in September

September hourly sunshine

Dayton average rain in September

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.

Other monthly averages

Best places to visit in September

UV index Best time to go?

Beta

Current (hourly) weather 15 day forecast

Dayton weather stats

Dayton weather statistics
Hottest month: July 28.1°C 82.6°F
Driest month: July 15mm 0.6ins
Sunniest month: July 13.6hrs
Coldest month: January 2.2°C 36°F
Wettest month: December 71mm 2.8ins
Map showing location of Dayton (46.32375, -117.97244) Dayton map pin © Google

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