September Weather in Trenton, United States

Last updated: June 24, 2025

In September, the average temperature in Trenton, United States hovers around 23°C (73°F), offering a pleasant climate. However, temperatures can fluctuate significantly, with a minimum of 8°C (46°F) and a maximum soaring to 35°C (95°F). Expect about 59 mm (2.3 in) of precipitation spread over 7 days, and high humidity levels at 79%, creating a tropical feel in the air.

September Temperature in Trenton

In September in Trenton, the average temperature is 23°C (73°F), with maximums reaching 35°C (95°F) and minimums dropping to 8°C (46°F). This range makes Trenton an ideal destination for travelers seeking pleasant weather and a variety of outdoor activities.

September Weather in Trenton: Daily Temperature Highs, Lows, and Averages

The chart illustrates September temperature patterns in Trenton, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Trenton, September typically has an average temperature of 23°C (73°F), with highs reaching up to 35°C (95°F) and lows dropping to around 8°C (46°F).
JanFebMarAprMayJunJulAugSepOctNovDec333648566877807773604540
Data source: Temperature data for Trenton generated using information from the Copernicus Climate Change Service.
Choose your preferred temperature unit
The average of daily temperatures (24 hours) calculated across all days in the month.

September Precipitation in Trenton

In Trenton in September, the precipitation amount is 59 mm (2.3 in) over a span of 7 days.

September Precipitation Trends in Trenton

The chart displays monthly precipitation patterns in Trenton, with values for each month alongside September’s data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how September’s conditions compare to those of other months. In Trenton, September typically receives around 59 mm (2.3 inches) of precipitation spread over approximately 7 days.
JanFebMarAprMayJunJulAugSepOctNovDec828714114417010092122591107971
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
Choose your preferred precipitation unit

September Humidity in Trenton

In Trenton in September humidity is 79%. With an average temperature of 23°C (73°F), this humidity feels like a warm embrace that clings to the skin, making travel feel both invigorating and slightly exhausting as the air wraps around you like a damp blanket.

September Average Humidity in Trenton

This chart illustrates the average monthly humidity levels in Trenton, with September’s data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, helping you understand how conditions vary by season. In September, average humidity in Trenton is approximately 79%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec84%82%84%83%80%83%82%83%79%79%88%87%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Trenton

In Trenton in September, the maximum UV index is 9, which corresponds to a very high Exposure Category. The time to burn is just 15 minutes, so it's essential to take precautions. For detailed information, you can check the Hourly UV Index in Trenton.

Maximum UV Index Levels in Trenton for September

The chart shows the monthly maximum UV Index (UVI) for Trenton in September, representing the highest UV radiation level. The UVI measures the intensity of ultraviolet radiation from the sun, indicating the potential risk of sunburn and UV-related health issues. In September, the maximum UV index in Trenton typically reaches 9, which falls under the very high exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec3579111110109753
Data source: Trenton September UVI data generated using information from the Copernicus Climate Change Service.

UV Risk Categories

  •  Extreme (11+): Avoid the sun, stay in shade.
  •  Very High (8-10): Limit sun exposure.
  •  High (6-7): Use SPF 30+ and protective clothing.
  •  Moderate (3-5): Midday shade recommended.
  •  Low (0-2): No protection needed.

How September Weather in Trenton Compares to Other Months

Weather in Trenton varies notably across the year, with each month offering distinct climate conditions. This page compares September’s weather to other months in Trenton, focusing on differences in temperature, rainfall, humidity, and UV levels.

This table compares monthly weather conditions in Trenton, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
 TemperaturePrecipitationHumidityUV
January Weather1°C (33°F)82 mm (3.2 inches)84%moderate
February Weather2°C (37°F)87 mm (3.4 inches)82%moderate
March Weather9°C (48°F)141 mm (5.6 inches)84%high
April Weather13°C (56°F)144 mm (5.7 inches)83%very high
May Weather20°C (68°F)170 mm (6.7 inches)80%extreme
June Weather25°C (78°F)100 mm (3.9 inches)83%extreme
July Weather27°C (80°F)92 mm (3.6 inches)82%very high
August Weather25°C (77°F)122 mm (4.8 inches)82%very high
September Weather23°C (73°F)59 mm (2.3 inches)79%very high
October Weather15°C (60°F)110 mm (4.3 inches)79%high
November Weather7°C (45°F)78 mm (3.1 inches)88%moderate
December Weather4°C (40°F)71 mm (2.8 inches)87%moderate

Compare Trenton's Climate with Cities Worldwide