Idaho Falls (ID)
September
Weather in Idaho Falls, Idaho for September 2025
Your guide to Idaho Falls weather in September - trends and predictions
In general, the average temperature in Idaho Falls at the beginning of September is 30.4 °F. As the month progressed, temperatures tended to significantly cool down, reaching an average of 25.9 °F by the end of September.
Idaho Falls experiences moderate rainfall in September, with an average of 6 rainy days and a total precipitation of 24.7 mm.
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Temperatures
Rain 🌧️
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24
Dry days
6
Rainy days
0
Snow days
26°/9°
Temperatures
21 km/h
Avg max wind
40 %
Avg humidity
Idaho Falls Weather September
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Temperatures trend during September in Idaho Falls
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September weather in Idaho Falls day by day
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| Date | Weather | Temperatures | Rain | UV | More |
|---|---|---|---|---|---|
| Sept. 1 |  Sunny | 34° /12° | 0 mm | 8 | |
| Sept. 2 |  Cloudy | 32° /14° | 0 mm | 7 | |
| Sept. 3 |  Moderate rain at times | 27° /13° | 0.6 mm | 6 | |
| Sept. 4 | Sunny | 26° /11° | 0 mm | 7 | |
| Sept. 5 | Sunny | 30° /10° | 0 mm | 8 | |
| Sept. 6 | Sunny | 32° /11° | 0 mm | 8 | |
| Sept. 7 |  Partly cloudy | 32° /12° | 0 mm | 8 | |
| Sept. 8 | Sunny | 32° /12° | 0 mm | 8 | |
| Sept. 9 | Sunny | 31° /13° | 0 mm | 8 | |
| Sept. 10 |  Overcast | 31° /13° | 0 mm | 7 | |
| Sept. 11 |  Patchy rain possible | 27° /14° | 0.3 mm | 6 | |
| Sept. 12 | Patchy rain possible | 14° /9° | 3.2 mm | 3 | |
| Sept. 13 | Sunny | 20° /5° | 0 mm | 6 | |
| Sept. 14 | Overcast | 25° /7° | 0 mm | 6 | |
| Sept. 15 | Cloudy | 28° /9° | 0 mm | 6 | |
| Sept. 16 |  Heavy rain at times | 25° /10° | 1.3 mm | 6 | |
| Sept. 17 | Heavy rain at times | 15° /8° | 17.4 mm | 4 | |
| Sept. 18 | Moderate rain at times | 15° /7° | 1.9 mm | 4 | |
| Sept. 19 | Sunny | 21° /6° | 0 mm | 6 | |
| Sept. 20 | Sunny | 23° /4° | 0 mm | 6 | |
| Sept. 21 | Sunny | 23° /5° | 0 mm | 6 | |
| Sept. 22 | Sunny | 22° /3° | 0 mm | 6 | |
| Sept. 23 | Partly cloudy | 22° /8° | 0 mm | 6 | |
| Sept. 24 | Sunny | 23° /6° | 0 mm | 6 | |
| Sept. 25 | Sunny | 28° /7° | 0 mm | 7 | |
| Sept. 26 | Cloudy | 27° /11° | 0 mm | 6 | |
| Sept. 27 | Sunny | 27° /9° | 0 mm | 7 | |
| Sept. 28 | Sunny | 30° /6° | 0 mm | 8 | |
| Sept. 29 | Sunny | 28° /10° | 0 mm | 7 | |
| Sept. 30 | Sunny | 18° /5° | 0 mm | 5 | |
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Important Notice
Our weather forecast for Idaho Falls 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 Idaho Falls forecast closer to your planned date for the most up-to-date weather information.
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Idaho Falls in September - FAQ
What are the expected maximum and minimum temperatures in Idaho Falls during September?
Enjoy moderate daytime temperatures of up to 26° and cooler nights around 9°. Ideal for a range of outdoor activities, from hiking to city tours.
How much rainfall should be expected in Idaho Falls during September?
In September, Idaho Falls can expect light to moderate rainfall, totaling 24.7 mm across approximately 6 days. Occasional showers are possible, and planning ahead for them could be helpful.
What are the typical wind conditions in Idaho Falls during September?
The average wind speed in Idaho Falls during September is 21 km/h, suggesting breezy to windy conditions, depending on your activities.
September rainfall patterns in Idaho Falls
Explore the daily rainfall trends and prepare for Idaho Fallss September weather 💧
UV exposure in Idaho Falls during September
Stay informed about UV levels for safe outdoor activities throughout the month of September ☀️
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