Waterville Weather in September

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

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

September is in the fall / autumn in Waterville and is typically the 4th warmest month of the year. Daytime maximum temperatures average around 21°C (70°F), whilst at night 6°C (43°F) is normal.

Waterville weather averages (imperial / metric)
Daytime temperature 20.9°C 69.5°F
Nightly temperature 6.2°C 43.1°F
Average temperature 13.5°C 56.3°F
Daily sunshine 8.1 hrs
Avg rainfall 18 mm 0.7 ins
Rainy days 6 days
Sea temperature 12.5°C 54.6°F
Humidity 59%
Windspeed 11.2kph 7 mph

On average September is the 2nd driest month of the year in Waterville with around 18mm 0.7 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 8.1 hours of sunshine per day.

September temperatures in Waterville

Waterville average temperature in September

September rainfall

Waterville average rain in September

September hourly sunshine

Waterville 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 Waterville 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

Waterville weather stats

Waterville weather statistics
Hottest month: July 26.7°C 80.1°F
Driest month: July 11mm 0.4ins
Sunniest month: July 11hrs
Coldest month: January -1.9°C 28.6°F
Wettest month: December 61mm 2.4ins
Map showing location of Waterville (47.64708, -120.07118) Waterville map pin © Google

Locations nearby

Top United States locations