May Weather in Princeton, United States

Last updated: June 24, 2025

In May, the average temperature in Princeton, United States is a pleasant 18°C (64°F). However, be prepared for a range of weather, as temperatures can dip to a chilly 2°C (35°F) or soar up to a sweltering 38°C (101°F). Expect 158 mm (6.2 in) of precipitation spread over about 16 days, with an average humidity level of 77%.

May Temperature in Princeton

In May in Princeton, the average temperature is 18°C (64°F). Maximum temperatures can reach up to 38°C (101°F), while the minimum can drop as low as 2°C (35°F). Be prepared for a wide range of temperatures during your travels, as pack layers to enjoy both warm and cooler moments.

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

The chart illustrates May 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, May typically has an average temperature of 18°C (64°F), with highs reaching up to 38°C (101°F) and lows dropping to around 2°C (35°F).

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

May Precipitation in Princeton

In Princeton in May, the total precipitation amount is 158 mm (6.2 in) that occurs over a span of 16 days.

May Precipitation Trends in Princeton

The chart displays monthly precipitation patterns in Princeton, with values for each month alongside May’s data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how May’s conditions compare to those of other months. In Princeton, May typically receives around 158 mm (6.2 inches) of precipitation spread over approximately 16 days.

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

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Millimeters (mm) Inches (in)

May Humidity in Princeton

In Princeton in May humidity is 77%. With an average temperature of 18°C (64°F), this humidity feels like a warm embrace, making it feel muggy and potentially uncomfortable for traveling, as sweat clings to your skin and the air thickens around you.

May Average Humidity in Princeton

This chart illustrates the average monthly humidity levels in Princeton, with May’s data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, helping you understand how conditions vary by season. In May, average humidity in Princeton is approximately 77%, offering insight into how humid the weather typically is during this month.

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

May UV Index in Princeton

In Princeton in May, the maximum UV index reaches 10, which corresponds to a very high Exposure Category. With a time to burn of just 15 minutes, it's crucial to take precautions. For more detailed information, you can check the Hourly UV Index in Princeton.

Maximum UV Index Levels in Princeton for May

The chart shows the monthly maximum UV Index (UVI) for Princeton in May, 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 May, the maximum UV index in Princeton typically reaches 10, which falls under the very high exposure category.

Data source: Princeton May 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 May 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 May’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 May’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	-4°C (26°F)	48 mm (1.9 inches)	78%	moderate
February Weather	-2°C (28°F)	44 mm (1.7 inches)	80%	moderate
March Weather	6°C (42°F)	103 mm (4.0 inches)	77%	high
April Weather	10°C (51°F)	78 mm (3.1 inches)	77%	very high
May Weather	18°C (64°F)	158 mm (6.2 inches)	77%	very high
June Weather	24°C (76°F)	124 mm (4.9 inches)	81%	extreme
July Weather	26°C (78°F)	106 mm (4.2 inches)	81%	extreme
August Weather	24°C (75°F)	88 mm (3.5 inches)	77%	very high
September Weather	21°C (70°F)	119 mm (4.7 inches)	73%	very high
October Weather	12°C (54°F)	154 mm (6.1 inches)	75%	high
November Weather	5°C (40°F)	55 mm (2.2 inches)	85%	moderate
December Weather	1°C (34°F)	34 mm (1.4 inches)	83%	moderate