New Haven County (New Haven)
September
Weather in New Haven County, Connecticut for September 2026
Your guide to New Haven County weather in September - trends and predictions
So far, September 2026 in New Haven County is slightly warmer than the historical average by 1 °F.
The forecast for the next days in New Haven County predicts temperatures to be around 17 °F, close to the historical average.
In general, the average temperature in New Haven County at the beginning of September is 23.1 °F. As the month progressed, temperatures tended to significantly cool down, reaching an average of 16.9 °F by the end of September.
New Haven County experiences moderate rainfall in September, with an average of 10 rainy days and a total precipitation of 108.6 mm.
New! Chat with our AI weatherman - it’s amazing and free.
Temperatures
Rain 🌧️
More
20
Dry days
10
Rainy days
0
Snow days
22°/16°
Temperatures
17 km/h
Avg max wind
75 %
Avg humidity
New Haven County Weather September
Move between months or click on a day
Temperatures trend during September in New Haven County
See the weather trend as well as the moving average line
September weather in New Haven County day by day
Click on a date for more information
| Date | Weather | Temperatures | Rain | UV | More |
|---|---|---|---|---|---|
| Sept. 1 |  Moderate or heavy rain shower | 24° /18° | 3.4 mm | 4 | |
| Sept. 2 |  Partly cloudy | 24° /16° | 0.2 mm | 4 | |
| Sept. 3 |  Sunny | 22° /15° | 3.3 mm | 4 | |
| Sept. 4 | Sunny | 23° /16° | 0.5 mm | 4 | |
| Sept. 5 | Sunny | 25° /17° | 12.1 mm | 7 | |
| Sept. 6 | Partly cloudy | 23° /17° | 4.2 mm | 5 | |
| Sept. 7 |  Heavy rain at times | 21° /14° | 8.7 mm | 5 | |
| Sept. 8 | Sunny | 23° /12° | 0 mm | 6 | |
| Sept. 9 | Partly cloudy | 24° /14° | 0.2 mm | 5 | |
| Sept. 10 | Sunny | 24° /17° | 0.2 mm | 5 | |
| Sept. 11 | Partly cloudy | 25° /15° | 0 mm | 7 | |
| Sept. 12 | Partly cloudy | 23° /14° | 0 mm | 6 | |
| Sept. 13 | Sunny | 23° /16° | 35 mm | 4 | |
| Sept. 14 |  Patchy rain possible | 24° /17° | 0 mm | 6 | |
| Sept. 15 | Partly cloudy | 21° /15° | 0 mm | 6 | |
| Sept. 16 |  Cloudy | 22° /14° | 0 mm | 5 | |
| Sept. 17 |  Overcast | 20° /15° | 0 mm | 5 | |
| Sept. 18 | Sunny | 26° /19° | 1.5 mm | 6.6 | |
| Sept. 19 | Overcast | 19° /13° | 0 mm | 6 | |
| Sept. 20 | Light rain shower | 17° /15° | 9.2 mm | 0.4 | |
| Sept. 21 | Light rain shower | 16° /13° | 29.2 mm | 4.4 | |
| Sept. 22 | Light rain shower | 13° /11° | 44.5 mm | 3 | |
| Sept. 23 | Patchy rain possible | 15° /11° | 0.7 mm | 4 | |
| Sept. 24 | Patchy rain possible | 17° /14° | 0.8 mm | 4 | |
| Sept. 25 | Patchy rain possible | 16° /12° | 42.2 mm | 4 | |
| Sept. 26 | Light rain shower | 15° /11° | 8 mm | 3 | |
| Sept. 27 | Overcast | 18° /12° | 0 mm | 4 | |
| Sept. 28 | Overcast | 20° /10° | 0 mm | 6 | |
| Sept. 29 | Patchy rain possible | 16° /12° | 9.1 mm | 4 | |
| Sept. 30 | Patchy rain possible | 16° /15° | 1.3 mm | 4 | |
| Next | |||||
Important Notice
Our weather forecast for New Haven 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 New Haven County forecast closer to your planned date for the most up-to-date weather information.
Change Month
New Haven County in September - FAQ
What are the expected maximum and minimum temperatures in New Haven County during September?
During September, expect a variety of temperatures with highs around 22° and lows near 16°, suitable for diverse activities and preferences.
How much rainfall should be expected in New Haven County during September?
Significant rainfall exceeding 108.6 mm is expected in New Haven County during September, occurring over more than 10 days. Preparing for wet conditions is recommended in your planning.
What are the typical wind conditions in New Haven County during September?
The average wind speed in New Haven County during September is 17 km/h, suggesting breezy to windy conditions, depending on your activities.
September rainfall patterns in New Haven County
Explore the daily rainfall trends and prepare for New Haven Countys September weather 💧
Typically, New Haven County has 10 rainy days in September with a total of 108.6 mm of rainfall.
UV exposure in New Haven County during September
Stay informed about UV levels for safe outdoor activities throughout the month of September ☀️
Top locations in New Haven County
Select a location for an accurate weather forecast
More Locations Quick links
More New Haven County weather pages
You are here
Where is New Haven County?Get accurate weather forecasts for New Haven County, located at latitude 41.308 and longitude -72.928. Stay updated with localized weather information tailored for New Haven County.
Found a mistake?
We appreciate your attention to details. Tell us here.