January Weather in Trenton, United States

Last updated: June 24, 2025

In January, the average temperature in Trenton, United States hovers around -4°C (25°F), with the potential to plunge to a chilly -23°C (-8°F) or rise to a brisk 11°C (51°F). Expect 98 mm (3.9 in) of precipitation spread over 9 days and a notable average humidity of 88%, making it a notably damp and cool time of year.

January Temperature in Trenton

In January in Trenton, the average temperature is -4°C (25°F), with maximums reaching 11°C (51°F) and minimums dropping as low as -23°C (-8°F). Travelers should be prepared for a wide range of temperatures and dress in layers to stay comfortable.

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

The chart illustrates January 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, January typically has an average temperature of -4°C (25°F), with highs reaching up to 11°C (51°F) and lows dropping to around -23°C (-8°F).

Data source: Temperature data for Trenton generated using information from the Copernicus Climate Change Service.

January Precipitation in Trenton

In Trenton in January, the precipitation amount is 98 mm (3.9 in) spread over a duration of 9 days.

January Precipitation Trends in Trenton

The chart displays monthly precipitation patterns in Trenton, with values for each month alongside January’s data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how January’s conditions compare to those of other months. In Trenton, January typically receives around 98 mm (3.9 inches) of precipitation spread over approximately 9 days.

Data source: Precipitation data for January generated using information from the Copernicus Climate Change Service.

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Millimeters (mm) Inches (in)

January Humidity in Trenton

In Trenton in January, humidity is 88%. With an average temperature of -4°C (25°F), this humidity feels like a biting chill that clings to your skin, making outdoor excursions brisk and invigorating, yet challenging as you navigate the frosty air.

January Average Humidity in Trenton

This chart illustrates the average monthly humidity levels in Trenton, with January’s data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, helping you understand how conditions vary by season. In January, average humidity in Trenton is approximately 88%, offering insight into how humid the weather typically is during this month.

Data source: Humidity data for January generated using information from the Copernicus Climate Change Service.

January UV Index in Trenton

In Trenton in January, the maximum UV index is 2, which corresponds to a low exposure category. With this level of UV radiation, the time to burn is approximately 45 minutes. To learn more about the hourly UV index in Trenton, you can visit Hourly UV Index in Trenton.

Maximum UV Index Levels in Trenton for January

The chart shows the monthly maximum UV Index (UVI) for Trenton in January, 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 January, the maximum UV index in Trenton typically reaches 2, which falls under the low exposure category.

Data source: Trenton January 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 January 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 January’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 January’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	-4°C (25°F)	98 mm (3.9 inches)	88%	low
February Weather	-3°C (26°F)	90 mm (3.6 inches)	88%	moderate
March Weather	0°C (32°F)	73 mm (2.9 inches)	85%	moderate
April Weather	6°C (43°F)	129 mm (5.1 inches)	81%	high
May Weather	11°C (52°F)	92 mm (3.6 inches)	76%	very high
June Weather	16°C (61°F)	79 mm (3.1 inches)	74%	very high
July Weather	19°C (67°F)	80 mm (3.2 inches)	74%	very high
August Weather	20°C (68°F)	73 mm (2.9 inches)	74%	very high
September Weather	16°C (61°F)	95 mm (3.7 inches)	77%	high
October Weather	11°C (52°F)	107 mm (4.2 inches)	82%	moderate
November Weather	4°C (40°F)	130 mm (5.1 inches)	85%	moderate
December Weather	-1°C (30°F)	138 mm (5.4 inches)	84%	low