January Weather in Princeton, United States

Last updated: June 24, 2025

In January, the average temperature in Princeton, United States is a pleasant 20°C (69°F). Expect a range from a cool 3°C (38°F) to a warm 30°C (86°F). During this time, you'll encounter approximately 25 mm (1.0 in) of precipitation spread over 4 days, resulting in an average humidity of 81%. Stay prepared for a mix of sunny and rainy days!

January Temperature in Princeton

In January in Princeton, the average temperature is 20°C (69°F). Maximums can reach 30°C (86°F), and minimums can be as low as 3°C (38°F). This pleasant climate makes it an ideal time for outdoor exploration and travel in Princeton.

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 20°C (69°F), with highs reaching up to 30°C (86°F) and lows dropping to around 3°C (38°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 precipitation amount is 25 mm (1.0 in) over the course of 4 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 25 mm (1.0 inches) of precipitation spread over approximately 4 days.

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

Choose your preferred precipitation unit

Millimeters (mm) Inches (in)

January Humidity in Princeton

In Princeton in January, humidity is 81%. With an average temperature of 20°C (69°F), this humidity feels like a thick blanket embracing you, making travel a bit uncomfortable and sticky.

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 81%, 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 is 6, which corresponds to a high Exposure Category. The time to burn is approximately 25 minutes. To find the hourly UV index in Princeton, you can refer to this Hourly UV Index in Princeton.

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 6, which falls under the high 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	20°C (69°F)	25 mm (1.0 inches)	81%	high
February Weather	23°C (73°F)	43 mm (1.7 inches)	79%	very high
March Weather	23°C (73°F)	27 mm (1.1 inches)	76%	very high
April Weather	25°C (78°F)	58 mm (2.3 inches)	73%	extreme
May Weather	26°C (80°F)	149 mm (5.9 inches)	71%	extreme
June Weather	28°C (82°F)	205 mm (8.1 inches)	69%	extreme
July Weather	28°C (84°F)	204 mm (8.0 inches)	70%	extreme
August Weather	29°C (84°F)	203 mm (8.0 inches)	72%	extreme
September Weather	28°C (83°F)	214 mm (8.4 inches)	76%	extreme
October Weather	27°C (81°F)	132 mm (5.2 inches)	79%	very high
November Weather	24°C (75°F)	69 mm (2.7 inches)	80%	very high
December Weather	22°C (71°F)	37 mm (1.4 inches)	81%	high