Prosser Weather in September

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

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

September is in the fall / autumn in Prosser and is typically the 4th warmest month of the year. Daytime maximum temperatures average around a comfortable 25°C (77°F), whilst at night 8°C (46°F) is normal.

Prosser weather averages (imperial / metric)
Daytime temperature 25.1°C 77.2°F
Nightly temperature 7.9°C 46.2°F
Average temperature 16.5°C 61.7°F
Daily sunshine 9.3 hrs
Avg rainfall 12 mm 0.5 ins
Rainy days 4 days
Sea temperature 13°C 55.4°F
Humidity 52%
Windspeed 12.6kph 8 mph

On average September is the 3rd driest month of the year in Prosser with around 12mm 0.5 inches of rain making it a dry time to visit. This rainfall is typically spread over 4 days, although this may vary considerably.

On the flip side this corresponds to an average of 9.3 hours of sunshine per day.

September temperatures in Prosser

Prosser average temperature in September

September rainfall

Prosser average rain in September

September hourly sunshine

Prosser 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 Prosser 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

Prosser weather stats

Prosser weather statistics
Hottest month: July 30°C 86°F
Driest month: July 6mm 0.2ins
Sunniest month: July 12.6hrs
Coldest month: January 3.4°C 38.1°F
Wettest month: December 30mm 1.2ins
Map showing location of Prosser (46.2068, -119.76892) Prosser map pin © Google

Locations nearby

Top United States locations