January Weather in Princeton, United States

Last updated: June 24, 2025

In January, the average temperature in Princeton, United States hovers around 1°C (34°F), with a possible low of -21°C (-5°F) and a high reaching up to 20°C (69°F). Expect around 77 mm (3.0 in) of precipitation over 10 days, coupled with an average humidity level of 87%—perfect for cozy indoor activities!

January Temperature in Princeton

In January in Princeton, the average temperature is 1°C (34°F), with maximums reaching 20°C (69°F) and minimums dipping as low as -21°C (-5°F). This range suggests a dramatic contrast in weather, so travelers should prepare for both chilly and relatively warm conditions during their visit.

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

The chart illustrates January temperature patterns in Princeton, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Princeton, January typically has an average temperature of 1°C (34°F), with highs reaching up to 20°C (69°F) and lows dropping to around -21°C (-5°F).

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

January Precipitation in Princeton

In Princeton in January, the total precipitation amount is 77 mm (3.0 in) spread over a duration of 10 days.

January Precipitation Trends in Princeton

The chart displays monthly precipitation patterns in Princeton, 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 Princeton, January typically receives around 77 mm (3.0 inches) of precipitation spread over approximately 10 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 Princeton

In Princeton in January humidity is 87%. With an average temperature of 1°C (34°F), this humidity feels like a chilling blanket enveloping you, making every step outside feel heavy and damp, and leaving you longing for warmth and comfort while traveling.

January Average Humidity in Princeton

This chart illustrates the average monthly humidity levels in Princeton, 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 Princeton is approximately 87%, 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 Princeton

In Princeton in January, the maximum UV index reaches 4, which corresponds to a moderate Exposure Category. With a time to burn of 30 minutes, it’s important to take precautions to protect your skin. You can find more details in the Hourly UV Index in Princeton for better planning.

Maximum UV Index Levels in Princeton for January

The chart shows the monthly maximum UV Index (UVI) for Princeton 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 Princeton typically reaches 4, which falls under the moderate exposure category.

Data source: Princeton 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 Princeton Compares to Other Months

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

This table compares monthly weather conditions in Princeton, showing how January’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	1°C (34°F)	77 mm (3.0 inches)	87%	moderate
February Weather	4°C (40°F)	124 mm (4.9 inches)	87%	high
March Weather	7°C (45°F)	100 mm (3.9 inches)	86%	very high
April Weather	11°C (53°F)	120 mm (4.7 inches)	84%	very high
May Weather	17°C (62°F)	133 mm (5.2 inches)	83%	extreme
June Weather	20°C (68°F)	119 mm (4.7 inches)	83%	extreme
July Weather	22°C (72°F)	78 mm (3.1 inches)	79%	extreme
August Weather	21°C (70°F)	109 mm (4.3 inches)	66%	very high
September Weather	19°C (66°F)	109 mm (4.3 inches)	68%	very high
October Weather	14°C (57°F)	115 mm (4.5 inches)	78%	high
November Weather	6°C (43°F)	72 mm (2.8 inches)	89%	moderate
December Weather	4°C (39°F)	96 mm (3.8 inches)	86%	moderate