Twin Falls County (Twin Falls)
September
Weather in Twin Falls County, Idaho for September 2026
Your guide to Twin Falls County weather in September - trends and predictions
Until now, September 2026 in Twin Falls County is slightly cooler than the historical average by 1.9 °F.
The forecast for the upcoming days in Twin Falls County predicts a temperature of 26.3 °F, which is slightly above the historical average.
In general, the average temperature in Twin Falls County at the beginning of September is 30 °F. As the month progressed, temperatures tended to significantly cool down, reaching an average of 24.9 °F by the end of September.
With an average of 3 rainy days, Twin Falls County experiences minimal rainfall in September.
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Temperatures
Rain 🌧️
More
27
Dry days
3
Rainy days
0
Snow days
28°/11°
Temperatures
22 km/h
Avg max wind
44 %
Avg humidity
Twin Falls County Weather September
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Temperatures trend during September in Twin Falls County
See the weather trend as well as the moving average line
September weather in Twin Falls County day by day
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| Date | Weather | Temperatures | Rain | UV | More |
|---|---|---|---|---|---|
| Sept. 1 |  Sunny | 33° /12° | 4.5 mm | 6 | |
| Sept. 2 |  Overcast | 31° /14° | 0 mm | 6 | |
| Sept. 3 | Overcast | 31° /14° | 0 mm | 8 | |
| Sept. 4 | Sunny | 29° /11° | 0 mm | 8 | |
| Sept. 5 | Sunny | 30° /11° | 0 mm | 8 | |
| Sept. 6 | Overcast | 28° /12° | 0 mm | 8 | |
| Sept. 7 |  Cloudy | 28° /10° | 0 mm | 8 | |
| Sept. 8 |  Partly cloudy | 29° /8° | 0 mm | 7 | |
| Sept. 9 | Overcast | 27° /12° | 0 mm | 6 | |
| Sept. 10 | Overcast | 29° /12° | 0 mm | 5 | |
| Sept. 11 | Cloudy | 26° /14° | 0.1 mm | 7 | |
| Sept. 12 |  Thundery outbreaks possible | 27° /8° | 0 mm | 6 | |
| Sept. 13 | Sunny | 24° /10° | 0 mm | 7 | |
| Sept. 14 | Thundery outbreaks possible | 24° /8° | 0 mm | 7 | |
| Sept. 15 | Partly cloudy | 25° /7° | 0 mm | 6 | |
| Sept. 16 | Sunny | 28° /7° | 0 mm | 6 | |
| Sept. 17 | Sunny | 29° /13° | 0.2 mm | 5 | |
| Sept. 18 | Sunny | 25° /10° | 0.4 mm | 6 | |
| Sept. 19 | Overcast | 25° /10° | 0.9 mm | 4 | |
| Sept. 20 | Overcast | 27° /12° | 1.9 mm | 6 | |
| Sept. 21 |  Light rain shower | 28° /12° | 2 mm | 5 | |
| Sept. 22 | Sunny | 23° /11° | 2.2 mm | 3 | |
| Sept. 23 | Sunny | 29° /11° | 0 mm | 5.8 | |
| Sept. 24 | Sunny | 31° /14° | 0 mm | 5.9 | |
| Sept. 25 | Overcast | 30° /15° | 0 mm | 5.2 | |
| Sept. 26 | Overcast | 23° /10° | 0 mm | 4.9 | |
| Sept. 27 | Overcast | 25° /9° | 0 mm | 6 | |
| Sept. 28 | Sunny | 16° /9° | 0.3 mm | 5 | |
| Sept. 29 | Sunny | 20° /8° | 0 mm | 6 | |
| Sept. 30 | Sunny | 29° /9° | 0 mm | 7 | |
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Important Notice
Our weather forecast for Twin Falls 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 Twin Falls County forecast closer to your planned date for the most up-to-date weather information.
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Twin Falls County in September - FAQ
What are the expected maximum and minimum temperatures in Twin Falls County during September?
Enjoy moderate daytime temperatures of up to 28° and cooler nights around 11°. Ideal for a range of outdoor activities, from hiking to city tours.
How much rainfall should be expected in Twin Falls County during September?
In September, Twin Falls County can expect light to moderate rainfall, totaling 39.9 mm across approximately 3 days. Occasional showers are possible, and planning ahead for them could be helpful.
What are the typical wind conditions in Twin Falls County during September?
The average wind speed in Twin Falls County during September is 22 km/h, suggesting breezy to windy conditions, depending on your activities.
September rainfall patterns in Twin Falls County
Explore the daily rainfall trends and prepare for Twin Falls Countys September weather 💧
Typically, Twin Falls County has 3 rainy days in September with a total of 39.9 mm of rainfall.
UV exposure in Twin Falls County during September
Stay informed about UV levels for safe outdoor activities throughout the month of September ☀️
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Where is Twin Falls County?Get accurate weather forecasts for Twin Falls County, located at latitude 42.563 and longitude -114.461. Stay updated with localized weather information tailored for Twin Falls County.
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