Arapahoe County (Littleton)
September
Weather in Arapahoe County, Colorado for September 2025
Your guide to Arapahoe County weather in September - trends and predictions
Until now, September 2025 in Arapahoe County is slightly cooler than the historical average by -1.4 °F.
Expect cooler weather in the next days in Arapahoe County with the forecast suggesting a temperature of 26 °F, lower than the historical average.
In general, the average temperature in Arapahoe County at the beginning of September is 27.4 °F. As the month progressed, temperatures tended to slightly decrease, reaching an average of 27.3 °F by the end of September.
With an average of 5 rainy days, Arapahoe County experiences minimal rainfall in September.
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Temperatures
Rain 🌧️
More
25
Dry days
5
Rainy days
0
Snow days
27°/14°
Temperatures
21 km/h
Avg max wind
35 %
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 | 28° /16° | 0 mm | 8 | |
| Sept. 2 | Sunny | 30° /14° | 0 mm | 8 | |
| Sept. 3 |  Patchy rain possible | 29° /15° | 0.1 mm | 7 | |
| Sept. 4 |  Patchy light rain | 31° /14° | 2.6 mm | 7 | |
| Sept. 5 |  Patchy light rain with thunder | 20° /12° | 0.7 mm | 5 | |
| Sept. 6 | Sunny | 25° /12° | 0 mm | 7 | |
| Sept. 7 |  Partly cloudy | 29° /15° | 0 mm | 7 | |
| Sept. 8 | Partly cloudy | 29° /15° | 0 mm | 7 | |
| Sept. 9 | Patchy rain possible | 28° /14° | 0.1 mm | 6 | |
| Sept. 10 | Patchy rain possible | 30° /15° | 3.2 mm | 7 | |
| Sept. 11 |  Moderate rain at times | 28° /16° | 3.6 mm | 6 | |
| Sept. 12 | Partly cloudy | 28° /15° | 0 mm | 7 | |
| Sept. 13 | Partly cloudy | 26° /13° | 3.2 mm | 6 | |
| Sept. 14 | Partly cloudy | 27° /13° | 3.2 mm | 7 | |
| Sept. 15 | Patchy rain possible | 29° /12° | 0.1 mm | 7 | |
| Sept. 16 | Patchy rain possible | 24° /12° | 4.5 mm | 1.4 | |
| Sept. 17 |  Thundery outbreaks possible | 19° /13° | 0 mm | 1.6 | |
| Sept. 18 | Partly cloudy | 22° /12° | 0 mm | 1.6 | |
| Sept. 19 | Sunny | 27° /9° | 0 mm | 1.8 | |
| Sept. 20 | Patchy rain possible | 29° /15° | 0.5 mm | 0 | |
| Sept. 21 | Sunny | 25° /16° | 0.1 mm | 5 | |
| Sept. 22 | Sunny | 27° /13° | 0 mm | 5 | |
| Sept. 23 | Sunny | 27° /13° | 0 mm | 5 | |
| Sept. 24 | Partly cloudy | 31° /15° | 0 mm | 6 | |
| Sept. 25 | Sunny | 28° /17° | 0 mm | 6 | |
| Sept. 26 | Sunny | 31° /16° | 0 mm | 6 | |
| Sept. 27 | Patchy rain possible | 30° /16° | 0.2 mm | 5 | |
| Sept. 28 | Sunny | 25° /12° | 0 mm | 5 | |
| Sept. 29 | Sunny | 19° /9° | 0 mm | 4 | |
| Sept. 30 | Partly cloudy | 27° /14° | 0 mm | 7 | |
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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 27° and cooler nights around 14°. 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 81.4 mm spread over approximately 5 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 21 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 💧
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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