Arapahoe County (Littleton)
September
Weather in Arapahoe County, Colorado for September 2026
Your guide to Arapahoe County weather in September - trends and predictions
So far, September 2026 in Arapahoe County is slightly warmer than the historical average by 1.4 °F.
The forecast for the next days in Arapahoe County predicts temperatures to be around 23 °F, close to the historical average.
In general, the average temperature in Arapahoe County at the beginning of September is 28.9 °F. As the month progressed, temperatures tended to significantly cool down, reaching an average of 23 °F by the end of September.
The climate of Arapahoe County in September is notably wet, with an average of 11 rainy days, and a total of 79.3 mm of precipitation.
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Temperatures
Rain 🌧️
More
19
Dry days
11
Rainy days
0
Snow days
26°/13°
Temperatures
19 km/h
Avg max wind
42 %
Avg humidity
Arapahoe County Weather September
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Temperatures trend during September in Arapahoe County
See the weather trend as well as the moving average line
September weather in Arapahoe County day by day
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| Date | Weather | Temperatures | Rain | UV | More |
|---|---|---|---|---|---|
| Sept. 1 |  Sunny | 29° /16° | 0 mm | 7 | |
| Sept. 2 | Sunny | 31° /14° | 0 mm | 8 | |
| Sept. 3 |  Patchy rain possible | 30° /14° | 0.1 mm | 8 | |
| Sept. 4 | Sunny | 31° /14° | 1.7 mm | 8 | |
| Sept. 5 |  Patchy light rain with thunder | 24° /13° | 2.1 mm | 6 | |
| Sept. 6 | Sunny | 27° /13° | 0 mm | 8 | |
| Sept. 7 |  Partly cloudy | 30° /16° | 0 mm | 6 | |
| Sept. 8 | Sunny | 29° /15° | 1.2 mm | 7 | |
| Sept. 9 |  Overcast | 28° /14° | 0 mm | 7 | |
| Sept. 10 | Patchy rain possible | 30° /14° | 2.1 mm | 7 | |
| Sept. 11 |  Moderate rain at times | 29° /15° | 2.4 mm | 7 | |
| Sept. 12 | Overcast | 28° /14° | 0 mm | 7 | |
| Sept. 13 | Overcast | 28° /13° | 2.2 mm | 7 | |
| Sept. 14 | Partly cloudy | 29° /14° | 2.2 mm | 5 | |
| Sept. 15 | Patchy rain possible | 27° /12° | 0.1 mm | 6 | |
| Sept. 16 | Patchy rain possible | 27° /13° | 10.2 mm | 4 | |
| Sept. 17 |  Cloudy | 25° /13° | 4.8 mm | 4 | |
| Sept. 18 | Sunny | 24° /11° | 1.1 mm | 4 | |
| Sept. 19 | Sunny | 26° /11° | 0.7 mm | 6 | |
| Sept. 20 | Overcast | 25° /12° | 0.4 mm | 6 | |
| Sept. 21 | Overcast | 23° /10° | 6.1 mm | 6 | |
| Sept. 22 |  Moderate rain | 21° /9° | 18.8 mm | 5 | |
| Sept. 23 |  Mist | 20° /9° | 2.7 mm | 3 | |
| Sept. 24 | Partly cloudy | 21° /11° | 2.1 mm | 4 | |
| Sept. 25 | Sunny | 27° /10° | 1.5 mm | 6 | |
| Sept. 26 | Sunny | 26° /10° | 0 mm | 6.6 | |
| Sept. 27 | Overcast | 27° /13° | 0 mm | 6.4 | |
| Sept. 28 | Overcast | 23° /14° | 0 mm | 4.1 | |
| Sept. 29 | Overcast | 16° /12° | 0.7 mm | 1.1 | |
| Sept. 30 | Overcast | 21° /11° | 0.7 mm | 6.5 | |
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Important Notice
Our weather forecast for Arapahoe 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 Arapahoe County forecast closer to your planned date for the most up-to-date weather information.
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Arapahoe County in September - FAQ
What are the expected maximum and minimum temperatures in Arapahoe County during September?
Enjoy moderate daytime temperatures of up to 26° and cooler nights around 13°. Ideal for a range of outdoor activities, from hiking to city tours.
How much rainfall should be expected in Arapahoe County during September?
Moderate rainfall is anticipated in Arapahoe County during September, with a total of 79.3 mm spread over approximately 11 days. Considering plans for rainy days is advisable.
What are the typical wind conditions in Arapahoe County during September?
The average wind speed in Arapahoe County during September is 19 km/h, suggesting breezy to windy conditions, depending on your activities.
September rainfall patterns in Arapahoe County
Explore the daily rainfall trends and prepare for Arapahoe Countys September weather 💧
Typically, Arapahoe County has 11 rainy days in September with a total of 79.3 mm of rainfall.
UV exposure in Arapahoe County during September
Stay informed about UV levels for safe outdoor activities throughout the month of September ☀️
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Where is Arapahoe County?Get accurate weather forecasts for Arapahoe County, located at latitude 39.613 and longitude -105.017. Stay updated with localized weather information tailored for Arapahoe County.
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