Typical Weather in Great Falls, MT in September
73° F Avg High
45° F Avg Low
4 Rainy Days
☀️ Temperature Summary
September is a popular time of year to visit, with an inviting climate characterized by warm temperatures. Highs in September are typically around 73°F, which is warmer than usual in Great Falls. You can expect overnight lows near 45°F most days. Temperatures will usually fall as the month goes on, with daily high temperatures ranging between 79°F and 66°F.
The warm, dry temperatures in September make Great Falls a great destination to relax and soak up the sun.
High Temps Throughout the Year
☔ Rain Summary
You can expect about a 13% chance of rain for any given day in September. It's one of the rainier months of the year for Great Falls, with total rainfall for the month around 2 inches.
Rainfall Throughout the Year
Planning a trip to Great Falls? Try our free trip weather planner