Jefferson County (Lakewood)
September
Weather in Jefferson County, Colorado for September 2025
Your guide to Jefferson County weather in September - trends and predictions
Until now, September 2025 in Jefferson County is slightly cooler than the historical average by -1.9 °F.
Expect cooler weather in the next days in Jefferson County with the forecast suggesting a temperature of 25.4 °F, lower than the historical average.
In general, the average temperature in Jefferson County at the beginning of September is 28.9 °F. As the month progressed, temperatures tended to noticeably cool down, reaching an average of 26.7 °F by the end of September.
Jefferson County experiences moderate rainfall in September, with an average of 6 rainy days and a total precipitation of 46.3 mm.
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Temperatures
Rain 🌧️
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24
Dry days
6
Rainy days
0
Snow days
27°/13°
Temperatures
17 km/h
Avg max wind
34 %
Avg humidity
Jefferson County Weather September
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Temperatures trend during September in Jefferson County
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September weather in Jefferson County day by day
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| Date | Weather | Temperatures | Rain | UV | More |
|---|---|---|---|---|---|
| Sept. 1 |  Sunny | 31° /15° | 0 mm | 7 | |
| Sept. 2 | Sunny | 31° /16° | 0 mm | 7 | |
| Sept. 3 |  Cloudy | 30° /17° | 0.8 mm | 7 | |
| Sept. 4 |  Partly cloudy | 30° /15° | 2.4 mm | 7 | |
| Sept. 5 | Partly cloudy | 23° /13° | 0.3 mm | 5 | |
| Sept. 6 | Sunny | 27° /12° | 0 mm | 7 | |
| Sept. 7 | Sunny | 30° /14° | 0 mm | 7 | |
| Sept. 8 | Sunny | 31° /15° | 0 mm | 8 | |
| Sept. 9 | Partly cloudy | 29° /14° | 0 mm | 7 | |
| Sept. 10 |  Patchy light rain with thunder | 28° /15° | 4 mm | 6 | |
| Sept. 11 |  Thundery outbreaks possible | 25° /15° | 3.4 mm | 6 | |
| Sept. 12 | Sunny | 27° /14° | 0 mm | 7 | |
| Sept. 13 |  Overcast | 25° /12° | 2 mm | 6 | |
| Sept. 14 | Overcast | 25° /12° | 2.3 mm | 6 | |
| Sept. 15 | Partly cloudy | 27° /12° | 0.1 mm | 6 | |
| Sept. 16 |  Patchy rain possible | 24° /13° | 4.6 mm | 1.4 | |
| Sept. 17 | Patchy rain possible | 18° /13° | 3.7 mm | 1.6 | |
| Sept. 18 | Partly cloudy | 20° /12° | 0 mm | 1.5 | |
| Sept. 19 | Sunny | 27° /9° | 0 mm | 1.8 | |
| Sept. 20 | Patchy rain possible | 28° /14° | 0.5 mm | 0 | |
| Sept. 21 | Sunny | 25° /15° | 0 mm | 5 | |
| Sept. 22 | Sunny | 28° /13° | 0 mm | 5 | |
| Sept. 23 | Sunny | 26° /12° | 0 mm | 5 | |
| Sept. 24 | Partly cloudy | 30° /14° | 0 mm | 6 | |
| Sept. 25 | Sunny | 27° /16° | 0 mm | 6 | |
| Sept. 26 | Sunny | 30° /15° | 0 mm | 6 | |
| Sept. 27 | Patchy rain possible | 29° /16° | 0.4 mm | 5 | |
| Sept. 28 | Sunny | 24° /12° | 0 mm | 5 | |
| Sept. 29 | Sunny | 19° /9° | 0 mm | 4 | |
| Sept. 30 | Partly cloudy | 28° /11° | 0 mm | 7 | |
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Important Notice
Our weather forecast for Jefferson 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 Jefferson County forecast closer to your planned date for the most up-to-date weather information.
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Jefferson County in September - FAQ
What are the expected maximum and minimum temperatures in Jefferson County during September?
Enjoy moderate daytime temperatures of up to 27° and cooler nights around 13°. Ideal for a range of outdoor activities, from hiking to city tours.
How much rainfall should be expected in Jefferson County during September?
In September, Jefferson County can expect light to moderate rainfall, totaling 46.3 mm across approximately 6 days. Occasional showers are possible, and planning ahead for them could be helpful.
What are the typical wind conditions in Jefferson County during September?
The average wind speed in Jefferson County during September is 17 km/h, suggesting breezy to windy conditions, depending on your activities.
September rainfall patterns in Jefferson County
Explore the daily rainfall trends and prepare for Jefferson Countys September weather 💧
UV exposure in Jefferson County during September
Stay informed about UV levels for safe outdoor activities throughout the month of September ☀️
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Where is Jefferson County?Get accurate weather forecasts for Jefferson County, located at latitude 39.705 and longitude -105.081. Stay updated with localized weather information tailored for Jefferson County.
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