The temperatures in Montana in September are comfortable with low of 10°C and and high up to 24°C.
The wather in Montana in September can vary between cold and nice weather days. Expect a few rainy days but usually not more than 3.
Our weather forecast can give you a great sense of what weather to expect in Montana in September 2025.
If you’re planning to visit Montana in the near future, we highly recommend that you review the 14 day weather forecast for Montana before you arrive.
Temperatures
24° / 10°
Rainy Days
2
Snowy Days
0
Dry Days
28
Rainfall
34
mm
Sun Hours
11.5
Hrs
