New Haven Weather in September

What's the weather like in New Haven (Connecticut) in September 2025?

The climate in New Haven during September can be summarized as warm and a little damp.

September is in the fall / autumn in New Haven and is typically the 4th warmest month of the year. Daytime maximum temperatures average around 23°C (74°F), whilst at night 13°C (55°F) is normal.

New Haven weather averages (imperial / metric)
Daytime temperature 23.3°C 73.9°F
Nightly temperature 12.9°C 55.2°F
Average temperature 18.1°C 64.6°F
Daily sunshine 8 hrs
Avg rainfall 85 mm 3.3 ins
Rainy days 8 days
Sea temperature 19.6°C 67.3°F
Humidity 74%
Windspeed 15.8kph 10 mph

On average September is the 5th driest month of the year in New Haven with around 85mm 3.3 inches of rain making it a a little damp time to visit. This rainfall is typically spread over 8 days, although this may vary considerably.

On the flip side this corresponds to an average of 8 hours of sunshine per day.

September temperatures in New Haven

New Haven average temperature in September

September rainfall

New Haven average rain in September

September hourly sunshine

New Haven average rain in September

The data used in these monthly averages covers a period of over 100 years right up until last year. As such they are a valid prediction of what to expect for the weather in New Haven in September 2025.

Other monthly averages

Best places to visit in September

UV index Best time to go?

Beta

Current (hourly) weather 15 day forecast

New Haven weather stats

New Haven weather statistics
Hottest month: July 27.2°C 81°F
Driest month: June 76mm 3ins
Sunniest month: August 9.1hrs
Coldest month: January 1.8°C 35.2°F
Wettest month: November 103mm 4.1ins
Map showing location of New Haven (41.30815, -72.92816) New Haven map pin © Google

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