Flathead County (Glacier National Park)
September
Weather in Flathead County, Montana for September 2027
Your guide to Flathead County weather in September - trends and predictions
In general, the average temperature in Flathead County at the beginning of September is 24.6 °C. As the month progressed, temperatures tended to significantly cool down, reaching an average of 19 °C by the end of September.
Flathead County experiences moderate rainfall in September, with an average of 8 rainy days and a total precipitation of 305.1 mm.
Is September a good time to visit Flathead County? check out the best time to travel to Flathead County page.
✨ Is September a good time to visit Flathead County? – Ask the AI Weatherman
Temperatures
Rain 🌧️
More
22
Dry days
8
Rainy days
0
Snow days
21°/9°
Temperatures
12 km/h
Avg max wind
58 %
Avg humidity
Flathead County Weather September
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Temperatures trend during September in Flathead County
See the weather trend as well as the moving average line
September weather in Flathead County day by day
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| Date | Weather | Temperatures | Rain | UV | More |
|---|---|---|---|---|---|
| Sept. 1 |  Overcast | 30° /12° | 0 mm | 6 | |
| Sept. 2 |  Light rain | 28° /10° | 4.9 mm | 6 | |
| Sept. 3 | Overcast | 23° /10° | 0.4 mm | 5 | |
| Sept. 4 |  Heavy rain | 21° /10° | 25.3 mm | 5 | |
| Sept. 5 |  Moderate rain | 23° /9° | 17.9 mm | 5 | |
| Sept. 6 | Heavy rain | 24° /9° | 30.4 mm | 5 | |
| Sept. 7 | Heavy rain | 23° /10° | 107.6 mm | 5 | |
| Sept. 8 | Heavy rain | 22° /10° | 46.1 mm | 5 | |
| Sept. 9 |  Sunny | 24° /10° | 0 mm | 5.6 | |
| Sept. 10 |  Patchy rain possible | 24° /10° | 1.5 mm | 5.5 | |
| Sept. 11 | Heavy rain | 19° /10° | 31.2 mm | 4 | |
| Sept. 12 | Light rain | 17° /9° | 5 mm | 3 | |
| Sept. 13 | Patchy rain possible | 18° /6° | 2.1 mm | 4 | |
| Sept. 14 | Patchy rain possible | 16° /7° | 0.9 mm | 3 | |
| Sept. 15 | Light rain | 16° /7° | 5.1 mm | 3 | |
| Sept. 16 | Sunny | 21° /7° | 0 mm | 5 | |
| Sept. 17 | Patchy rain possible | 23° /9° | 0.8 mm | 4.9 | |
| Sept. 18 | Light rain | 22° /10° | 6.9 mm | 4.8 | |
| Sept. 19 | Overcast | 22° /9° | 0 mm | 4 | |
| Sept. 20 | Patchy rain possible | 21° /9° | 0.1 mm | 4.6 | |
| Sept. 21 | Light rain | 18° /7° | 2.7 mm | 4 | |
| Sept. 22 | Overcast | 19° /7° | 0 mm | 4 | |
| Sept. 23 |  Partly cloudy | 21° /8° | 0 mm | 4.4 | |
| Sept. 24 | Sunny | 24° /8° | 0 mm | 4.3 | |
| Sept. 25 | Patchy rain possible | 25° /10° | 0.6 mm | 4.2 | |
| Sept. 26 | Patchy rain possible | 15° /8° | 1.7 mm | 4 | |
| Sept. 27 |  Cloudy | 17° /3° | 0 mm | 4 | |
| Sept. 28 | Partly cloudy | 20° /6° | 0 mm | 3.9 | |
| Sept. 29 | Overcast | 17° /8° | 0.5 mm | 3 | |
| Sept. 30 | Moderate rain | 14° /7° | 13.2 mm | 3 | |
| Next | |||||
Important Notice
Our weather forecast for Flathead County 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 Flathead County forecast closer to your planned date for the most up-to-date weather information.
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Flathead County in September - FAQ
What are the expected maximum and minimum temperatures in Flathead County during September?
Enjoy moderate daytime temperatures of up to 21° and cooler nights around 9°. Ideal for a range of outdoor activities, from hiking to city tours.
How much rainfall should be expected in Flathead County during September?
Significant rainfall exceeding 305.1 mm is expected in Flathead County during September, occurring over more than 8 days. Preparing for wet conditions is recommended in your planning.
What are the typical wind conditions in Flathead County during September?
The average wind speed in Flathead County during September is 12 km/h, suggesting breezy to windy conditions, depending on your activities.
September rainfall patterns in Flathead County
Explore the daily rainfall trends and prepare for Flathead Countys September weather 💧
Typically, Flathead County has 8 rainy days in September with a total of 305.1 mm of rainfall.
UV exposure in Flathead County during September
Stay informed about UV levels for safe outdoor activities throughout the month of September ☀️
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