Trenton Weather in September

What's the weather like in Trenton (New Jersey) in September 2025?

The climate in Trenton during September can be summarized as warm and damp.

September is in the fall / autumn in Trenton and is typically the 4th warmest month of the year. Daytime maximum temperatures average around 26°C (78°F), whilst at night 13°C (56°F) is normal.

Trenton weather averages (imperial / metric)
Daytime temperature 25.6°C 78.1°F
Nightly temperature 13.2°C 55.8°F
Average temperature 19.4°C 66.9°F
Daily sunshine 7.8 hrs
Avg rainfall 102 mm 4 ins
Rainy days 8 days
Sea temperature 21°C 69.8°F
Humidity 72%
Windspeed 14.8kph 9 mph

On average September is the 3rd wettest month of the year in Trenton with around 102mm 4 inches of rain making it a 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 7.8 hours of sunshine per day.

September temperatures in Trenton

Trenton average temperature in September

September rainfall

Trenton average rain in September

September hourly sunshine

Trenton 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 Trenton 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

Trenton weather stats

Trenton weather statistics
Hottest month: July 29.9°C 85.8°F
Driest month: February 75mm 3ins
Sunniest month: August 8.9hrs
Coldest month: January 3.5°C 38.3°F
Wettest month: July 123mm 4.8ins
Map showing location of Trenton (40.21705, -74.74294) Trenton map pin © Google

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