New Haven County (New Haven)
September
Weather in New Haven County, Connecticut for September 2025
Your guide to New Haven County weather in September - trends and predictions
In general, the average temperature in New Haven County at the beginning of September is 22.3 °F. As the month progressed, temperatures tended to significantly cool down, reaching an average of 19.1 °F by the end of September.
New Haven County experiences moderate rainfall in September, with an average of 7 rainy days and a total precipitation of 47.7 mm.
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Temperatures
Rain 🌧️
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23
Dry days
7
Rainy days
0
Snow days
22°/15°
Temperatures
18 km/h
Avg max wind
74 %
Avg humidity
New Haven County Weather September
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Temperatures trend during September in New Haven County
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September weather in New Haven County day by day
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| Date | Weather | Temperatures | Rain | UV | More |
|---|---|---|---|---|---|
| Sept. 1 |  Moderate or heavy rain shower | 25° /20° | 5.6 mm | 6 | |
| Sept. 2 |  Partly cloudy | 24° /16° | 0 mm | 6 | |
| Sept. 3 |  Sunny | 21° /11° | 0 mm | 6 | |
| Sept. 4 | Sunny | 22° /13° | 0 mm | 6 | |
| Sept. 5 | Sunny | 21° /15° | 0 mm | 6 | |
| Sept. 6 | Partly cloudy | 23° /13° | 0 mm | 6 | |
| Sept. 7 |  Heavy rain at times | 20° /14° | 8.6 mm | 5 | |
| Sept. 8 | Sunny | 20° /10° | 0 mm | 6 | |
| Sept. 9 | Partly cloudy | 23° /12° | 0 mm | 6 | |
| Sept. 10 | Sunny | 24° /15° | 0 mm | 6 | |
| Sept. 11 | Partly cloudy | 22° /13° | 0 mm | 6 | |
| Sept. 12 | Partly cloudy | 23° /13° | 0 mm | 6 | |
| Sept. 13 | Sunny | 24° /14° | 0 mm | 6 | |
| Sept. 14 |  Patchy rain possible | 25° /17° | 0.1 mm | 6 | |
| Sept. 15 | Partly cloudy | 23° /16° | 0 mm | 6 | |
| Sept. 16 |  Cloudy | 22° /13° | 0 mm | 5 | |
| Sept. 17 |  Overcast | 22° /15° | 0 mm | 5 | |
| Sept. 18 | Overcast | 23° /16° | 0 mm | 5 | |
| Sept. 19 | Overcast | 24° /18° | 0 mm | 5 | |
| Sept. 20 | Overcast | 23° /18° | 0 mm | 5 | |
| Sept. 21 | Sunny | 22° /15° | 0.1 mm | 6 | |
| Sept. 22 | Partly cloudy | 20° /14° | 0 mm | 6 | |
| Sept. 23 | Cloudy | 20° /13° | 0 mm | 5 | |
| Sept. 24 | Cloudy | 19° /12° | 0 mm | 4 | |
| Sept. 25 | Overcast | 17° /14° | 5.6 mm | 4 | |
| Sept. 26 | Heavy rain at times | 22° /16° | 22 mm | 5 | |
| Sept. 27 | Patchy rain possible | 20° /18° | 3 mm | 5 | |
| Sept. 28 | Patchy rain possible | 21° /17° | 0.3 mm | 5 | |
| Sept. 29 | Moderate rain at times | 17° /15° | 2.4 mm | 4 | |
| Sept. 30 | Overcast | 18° /14° | 0 mm | 4 | |
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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 15°, suitable for diverse activities and preferences.
How much rainfall should be expected in New Haven County during September?
In September, New Haven County can expect light to moderate rainfall, totaling 47.7 mm across approximately 7 days. Occasional showers are possible, and planning ahead for them could be helpful.
What are the typical wind conditions in New Haven County during September?
The average wind speed in New Haven County during September is 18 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 💧
UV exposure in New Haven County during September
Stay informed about UV levels for safe outdoor activities throughout the month of September ☀️
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