Jefferson County (Lakewood)
September
Weather in Jefferson County, Colorado for September 2026
Your guide to Jefferson County weather in September - trends and predictions
So far, September 2026 in Jefferson County is slightly warmer than the historical average by 1.6 °F.
The forecast for the coming days of September 2026 predicts a temperature of 24 °F , which is warmer than usual.
In general, the average temperature in Jefferson County at the beginning of September is 30 °F. As the month progressed, temperatures tended to significantly cool down, reaching an average of 25.3 °F by the end of September.
Jefferson County experiences moderate rainfall in September, with an average of 10 rainy days and a total precipitation of 55.7 mm.
New! Chat with our AI weatherman - it’s amazing and free.
Temperatures
Rain 🌧️
More
20
Dry days
10
Rainy days
0
Snow days
26°/12°
Temperatures
16 km/h
Avg max wind
39 %
Avg humidity
Jefferson County Weather September
Move between months or click on a day
Temperatures trend during September in Jefferson County
See the weather trend as well as the moving average line
September weather in Jefferson County day by day
Click on a date for more information
| Date | Weather | Temperatures | Rain | UV | More |
|---|---|---|---|---|---|
| Sept. 1 |  Sunny | 31° /16° | 0 mm | 7 | |
| Sept. 2 | Sunny | 32° /17° | 0 mm | 8 | |
| Sept. 3 |  Cloudy | 31° /17° | 0.6 mm | 8 | |
| Sept. 4 | Sunny | 31° /16° | 1.8 mm | 8 | |
| Sept. 5 |  Partly cloudy | 25° /15° | 0.3 mm | 7 | |
| Sept. 6 | Sunny | 29° /14° | 0.5 mm | 7 | |
| Sept. 7 | Sunny | 31° /16° | 0.1 mm | 6 | |
| Sept. 8 | Sunny | 30° /17° | 0.4 mm | 7 | |
| Sept. 9 |  Overcast | 29° /14° | 0 mm | 8 | |
| Sept. 10 |  Patchy light rain with thunder | 29° /15° | 3 mm | 7 | |
| Sept. 11 |  Thundery outbreaks possible | 27° /15° | 2.6 mm | 6 | |
| Sept. 12 | Overcast | 27° /14° | 0 mm | 7 | |
| Sept. 13 | Overcast | 27° /13° | 1.5 mm | 7 | |
| Sept. 14 | Overcast | 27° /14° | 1.8 mm | 5 | |
| Sept. 15 | Partly cloudy | 26° /12° | 0.1 mm | 7 | |
| Sept. 16 | Partly cloudy | 26° /12° | 7.2 mm | 5 | |
| Sept. 17 | Cloudy | 25° /12° | 2 mm | 5 | |
| Sept. 18 | Cloudy | 25° /11° | 1.4 mm | 5 | |
| Sept. 19 | Overcast | 25° /11° | 0.5 mm | 6 | |
| Sept. 20 |  Patchy rain possible | 25° /12° | 1.2 mm | 6 | |
| Sept. 21 | Overcast | 24° /10° | 4.6 mm | 6 | |
| Sept. 22 | Patchy rain possible | 23° /10° | 14.6 mm | 5 | |
| Sept. 23 | Overcast | 23° /9° | 1.9 mm | 4 | |
| Sept. 24 | Partly cloudy | 23° /11° | 0.9 mm | 5 | |
| Sept. 25 | Sunny | 26° /10° | 0.9 mm | 6 | |
| Sept. 26 | Sunny | 29° /10° | 0 mm | 7 | |
| Sept. 27 | Sunny | 28° /14° | 0.1 mm | 6 | |
| Sept. 28 | Partly cloudy | 28° /12° | 0.3 mm | 6 | |
| Sept. 29 | Overcast | 23° /17° | 0 mm | 4.7 | |
| Sept. 30 | Patchy rain possible | 20° /15° | 0.8 mm | 3.6 | |
| Next | |||||
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.
Change Month
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 26° and cooler nights around 12°. Ideal for a range of outdoor activities, from hiking to city tours.
How much rainfall should be expected in Jefferson County during September?
Moderate rainfall is anticipated in Jefferson County during September, with a total of 55.7 mm spread over approximately 10 days. Considering plans for rainy days is advisable.
What are the typical wind conditions in Jefferson County during September?
The average wind speed in Jefferson County during September is 16 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 💧
Typically, Jefferson County has 10 rainy days in September with a total of 55.7 mm of rainfall.
UV exposure in Jefferson County during September
Stay informed about UV levels for safe outdoor activities throughout the month of September ☀️
Top locations in Jefferson County
Select a location for an accurate weather forecast
More Locations Quick links
More Jefferson County weather pages
You are here
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.
Found a mistake?
We appreciate your attention to details. Tell us here.