Yellowstone County (Billings)
September
Weather in Yellowstone County, Montana for September 2027
Your guide to Yellowstone County weather in September - trends and predictions
In general, the average temperature in Yellowstone County at the beginning of September is 30.1 °C. As the month progressed, temperatures tended to significantly cool down, reaching an average of 26.2 °C by the end of September.
With an average of 4 rainy days, Yellowstone County experiences minimal rainfall in September.
Is September a good time to visit Yellowstone County? check out the best time to travel to Yellowstone County page.
✨ Is September a good time to visit Yellowstone County? – Ask the AI Weatherman
Temperatures
Rain 🌧️
More
26
Dry days
4
Rainy days
0
Snow days
26°/11°
Temperatures
20 km/h
Avg max wind
46 %
Avg humidity
Yellowstone County Weather September
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Temperatures trend during September in Yellowstone County
See the weather trend as well as the moving average line
September weather in Yellowstone County day by day
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| Date | Weather | Temperatures | Rain | UV | More |
|---|---|---|---|---|---|
| Sept. 1 |  Sunny | 31° /12° | 0.2 mm | 6 | |
| Sept. 2 | Sunny | 35° /15° | 0 mm | 6.9 | |
| Sept. 3 |  Overcast | 29° /16° | 0.1 mm | 6 | |
| Sept. 4 |  Cloudy | 29° /13° | 0 mm | 6 | |
| Sept. 5 | Sunny | 27° /11° | 0 mm | 6.7 | |
| Sept. 6 | Sunny | 30° /10° | 0.1 mm | 6.6 | |
| Sept. 7 | Sunny | 30° /12° | 0 mm | 6.5 | |
| Sept. 8 | Sunny | 31° /14° | 0.2 mm | 6.4 | |
| Sept. 9 |  Partly cloudy | 30° /14° | 0 mm | 6.3 | |
| Sept. 10 | Overcast | 31° /13° | 0 mm | 6.2 | |
| Sept. 11 |  Light rain | 27° /13° | 3 mm | 6 | |
| Sept. 12 | Light rain | 22° /11° | 4.6 mm | 4 | |
| Sept. 13 |  Moderate rain | 22° /11° | 21.1 mm | 5 | |
| Sept. 14 | Overcast | 25° /8° | 0.1 mm | 5.8 | |
| Sept. 15 | Light rain | 25° /11° | 2.8 mm | 5.7 | |
| Sept. 16 | Light rain | 22° /10° | 6.4 mm | 5.6 | |
| Sept. 17 | Overcast | 25° /12° | 0.1 mm | 4 | |
| Sept. 18 | Moderate rain | 22° /11° | 20.2 mm | 4 | |
| Sept. 19 | Moderate rain | 22° /10° | 15.2 mm | 4 | |
| Sept. 20 | Light rain | 23° /11° | 3.4 mm | 5 | |
| Sept. 21 | Sunny | 22° /8° | 0.1 mm | 5 | |
| Sept. 22 | Light rain | 22° /8° | 4.5 mm | 5 | |
| Sept. 23 | Overcast | 24° /9° | 0 mm | 5 | |
| Sept. 24 | Sunny | 27° /10° | 0 mm | 4.9 | |
| Sept. 25 | Sunny | 30° /11° | 0 mm | 4.8 | |
| Sept. 26 | Sunny | 25° /12° | 0 mm | 4.7 | |
| Sept. 27 | Sunny | 25° /7° | 0 mm | 4.6 | |
| Sept. 28 | Sunny | 26° /9° | 0 mm | 4.6 | |
| Sept. 29 | Sunny | 29° /11° | 0 mm | 4.5 | |
| Sept. 30 | Overcast | 23° /9° | 0 mm | 4.4 | |
| Next | |||||
Important Notice
Our weather forecast for Yellowstone 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 Yellowstone County forecast closer to your planned date for the most up-to-date weather information.
Change Month
Yellowstone County in September - FAQ
What are the expected maximum and minimum temperatures in Yellowstone County during September?
Enjoy moderate daytime temperatures of up to 26° and cooler nights around 11°. Ideal for a range of outdoor activities, from hiking to city tours.
How much rainfall should be expected in Yellowstone County during September?
Moderate rainfall is anticipated in Yellowstone County during September, with a total of 82 mm spread over approximately 4 days. Considering plans for rainy days is advisable.
What are the typical wind conditions in Yellowstone County during September?
The average wind speed in Yellowstone County during September is 20 km/h, suggesting breezy to windy conditions, depending on your activities.
September rainfall patterns in Yellowstone County
Explore the daily rainfall trends and prepare for Yellowstone Countys September weather 💧
Typically, Yellowstone County has 4 rainy days in September with a total of 82 mm of rainfall.
UV exposure in Yellowstone County during September
Stay informed about UV levels for safe outdoor activities throughout the month of September ☀️
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