Missoula Weather in September

What's the weather like in Missoula (Montana) in September 2025?

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

September is in the fall / autumn in Missoula and is typically the 4th warmest month of the year. Daytime maximum temperatures average around a cool 20°C (68°F), whilst at night 3°C (37°F) is normal.

Missoula weather averages (imperial / metric)
Daytime temperature 20.2°C 68.4°F
Nightly temperature 3°C 37.4°F
Average temperature 11.6°C 52.9°F
Daily sunshine 9.2 hrs
Avg rainfall 33 mm 1.3 ins
Rainy days 8 days
Sea temperature 13.6°C 56.5°F
Humidity 62%
Windspeed 11.9kph 7 mph

On average September is the 4th wettest month of the year in Missoula with around 33mm 1.3 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 9.2 hours of sunshine per day.

September temperatures in Missoula

Missoula average temperature in September

September rainfall

Missoula average rain in September

September hourly sunshine

Missoula 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 Missoula 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

Missoula weather stats

Missoula weather statistics
Hottest month: July 26.6°C 79.9°F
Driest month: February 20mm 0.8ins
Sunniest month: July 13.1hrs
Coldest month: January -1.3°C 29.7°F
Wettest month: June 54mm 2.1ins
Map showing location of Missoula (46.87215, -113.994) Missoula map pin © Google

Locations nearby

Top United States locations