Montana (Billings)
September
Weather in Montana for September 2026
Your guide to Montana weather in September - trends and predictions
Until now, September 2026 in Montana is slightly cooler than the historical average by 1.3 °F.
The forecast for the next days in Montana predicts a temperature of 20.9 °F, which is cooler than the historical average.
In general, the average temperature in Montana at the beginning of September is 30.4 °F. As the month progressed, temperatures tended to significantly cool down, reaching an average of 26 °F by the end of September.
Montana experiences moderate rainfall in September, with an average of 7 rainy days and a total precipitation of 90.7 mm.
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Temperatures
Rain 🌧️
More
23
Dry days
7
Rainy days
0
Snow days
27°/11°
Temperatures
20 km/h
Avg max wind
46 %
Avg humidity
Montana Weather September
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What’s the Weather Like in Montana This September?
Discover the average temperatures and weather trends across Montana’s cities this September.
Temperatures trend during September in Montana
See the weather trend as well as the moving average line
September weather in Montana day by day
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| Date | Weather | Temperatures | Rain | UV | More |
|---|---|---|---|---|---|
| Sept. 1 |  Sunny | 32° /12° | 0.2 mm | 6 | |
| Sept. 2 | Sunny | 35° /15° | 0 mm | 8 | |
| Sept. 3 |  Overcast | 30° /15° | 0.1 mm | 6 | |
| Sept. 4 |  Cloudy | 29° /13° | 0 mm | 6 | |
| Sept. 5 | Sunny | 27° /10° | 0 mm | 7 | |
| Sept. 6 | Sunny | 30° /10° | 0.1 mm | 7 | |
| Sept. 7 | Sunny | 30° /12° | 0 mm | 7 | |
| Sept. 8 | Sunny | 31° /13° | 0.2 mm | 8 | |
| Sept. 9 |  Partly cloudy | 30° /13° | 0 mm | 8 | |
| Sept. 10 | Overcast | 31° /13° | 0 mm | 7 | |
| Sept. 11 |  Patchy rain possible | 27° /13° | 3 mm | 6 | |
| Sept. 12 |  Heavy rain at times | 22° /10° | 4.6 mm | 4 | |
| Sept. 13 | Cloudy | 22° /11° | 21.1 mm | 5 | |
| Sept. 14 | Overcast | 25° /8° | 0.1 mm | 6 | |
| Sept. 15 | Partly cloudy | 25° /10° | 2.8 mm | 6 | |
| Sept. 16 | Sunny | 22° /10° | 6.4 mm | 6 | |
| Sept. 17 | Overcast | 25° /11° | 0.1 mm | 4 | |
| Sept. 18 |  Moderate or heavy rain shower | 22° /10° | 20.2 mm | 4 | |
| Sept. 19 | Partly cloudy | 22° /10° | 15.2 mm | 4 | |
| Sept. 20 | Sunny | 23° /10° | 3.4 mm | 5 | |
| Sept. 21 | Sunny | 23° /8° | 0.1 mm | 5 | |
| Sept. 22 | Sunny | 22° /8° | 4.5 mm | 5 | |
| Sept. 23 | Overcast | 25° /9° | 0 mm | 5 | |
| Sept. 24 | Sunny | 27° /9° | 0 mm | 6 | |
| Sept. 25 | Sunny | 30° /11° | 0 mm | 7 | |
| Sept. 26 | Sunny | 25° /12° | 0 mm | 6 | |
| Sept. 27 | Sunny | 25° /7° | 0 mm | 5 | |
| Sept. 28 | Sunny | 26° /9° | 0 mm | 5 | |
| Sept. 29 | Sunny | 26° /11° | 0 mm | 4.7 | |
| Sept. 30 | Sunny | 23° /13° | 0 mm | 4.8 | |
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Important Notice
Our weather forecast for Montana in September is based on the analysis of historical data rather than real-time forecast models. While this provides a general overview, weather conditions can change. We recommend that you check the Montana forecast closer to your planned date for the most up-to-date weather information.
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Montana in September - FAQ
What are the expected maximum and minimum temperatures in Montana during September?
Enjoy moderate daytime temperatures of up to 27° and cooler nights around 11°. Ideal for a range of outdoor activities, from hiking to city tours.
How much rainfall should be expected in Montana during September?
Moderate rainfall is anticipated in Montana during September, with a total of 90.7 mm spread over approximately 7 days. Considering plans for rainy days is advisable.
What are the typical wind conditions in Montana during September?
The average wind speed in Montana during September is 20 km/h, suggesting breezy to windy conditions, depending on your activities.
September rainfall patterns in Montana
Explore the daily rainfall trends and prepare for Montanas September weather 💧
Typically, Montana has 7 rainy days in September with a total of 90.7 mm of rainfall.
UV exposure in Montana during September
Stay informed about UV levels for safe outdoor activities throughout the month of September ☀️
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