December Weather in Princeton, United States

Last updated: June 24, 2025

In Princeton, United States, the average temperature in December hovers around 9°C (48°F). Expect a chilly minimum of -8°C (18°F), with occasional warmth peaking at 25°C (77°F). During this month, anticipate approximately 109 mm (4.3 in) of precipitation spread over 9 days, contributing to a high average humidity of 86%. Prepare accordingly for a mix of cool temperatures and damp days!

December Temperature in Princeton

In December in Princeton, the average temperature is 9°C (48°F), with maximums reaching 25°C (77°F) and minimums plummeting as low as -8°C (18°F). Pack accordingly to enjoy a comfortable visit, as the weather can vary greatly during this time.

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

The chart illustrates December 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, December typically has an average temperature of 9°C (48°F), with highs reaching up to 25°C (77°F) and lows dropping to around -8°C (18°F).

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

December Precipitation in Princeton

In Princeton in December, the total precipitation amount is 109 mm (4.3 in) spread over 9 days.

December Precipitation Trends in Princeton

The chart displays monthly precipitation patterns in Princeton, with values for each month alongside December’s data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how December’s conditions compare to those of other months. In Princeton, December typically receives around 109 mm (4.3 inches) of precipitation spread over approximately 9 days.

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

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Millimeters (mm) Inches (in)

December Humidity in Princeton

In Princeton in December, humidity is 86%. With an average temperature of 9°C (48°F), this humidity feels like a damp chill that wraps around you, making outdoor activities uncomfortable and travel less enjoyable.

December Average Humidity in Princeton

This chart illustrates the average monthly humidity levels in Princeton, with December’s data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, helping you understand how conditions vary by season. In December, average humidity in Princeton is approximately 86%, offering insight into how humid the weather typically is during this month.

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

December UV Index in Princeton

In Princeton in December, the maximum UV index is 3, which corresponds to a moderate Exposure Category. The time to burn is approximately 30 minutes. For more details on the hourly UV index in Princeton, you can check the information here.

Maximum UV Index Levels in Princeton for December

The chart shows the monthly maximum UV Index (UVI) for Princeton in December, 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 December, the maximum UV index in Princeton typically reaches 3, which falls under the moderate exposure category.

Data source: Princeton December 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 December 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 December’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 December’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	7°C (45°F)	92 mm (3.6 inches)	85%	moderate
February Weather	10°C (50°F)	92 mm (3.6 inches)	82%	high
March Weather	12°C (54°F)	73 mm (2.9 inches)	81%	very high
April Weather	17°C (63°F)	106 mm (4.2 inches)	80%	very high
May Weather	22°C (72°F)	118 mm (4.7 inches)	81%	very high
June Weather	25°C (77°F)	125 mm (4.9 inches)	81%	extreme
July Weather	27°C (81°F)	124 mm (4.9 inches)	81%	extreme
August Weather	26°C (79°F)	158 mm (6.2 inches)	80%	very high
September Weather	24°C (75°F)	134 mm (5.3 inches)	79%	very high
October Weather	19°C (66°F)	68 mm (2.7 inches)	80%	very high
November Weather	11°C (53°F)	84 mm (3.3 inches)	85%	moderate
December Weather	9°C (48°F)	109 mm (4.3 inches)	86%	moderate