UV Index in Princeton, United States

Last updated: July 2, 2025

Understanding the UV Index in Princeton, United States is crucial for anyone looking to protect their skin and overall health. With UV levels peaking at 11 around midday, the risk of sunburn and long-term skin damage increases significantly, making awareness essential for enjoying outdoor activities safely. Princeton's temperate climate contributes to varying UV exposure throughout the year, and knowing when to take preventive measures can mean the difference between a fun day in the sun and painful consequences. Stay informed, stay protected, and enjoy all that Princeton has to offer while safeguarding your skin!

Hourly UV Index in Princeton

The UV Index for the day showcases a striking pattern, starting moderate at 7:00 AM with a value of 1. As the sun climbs higher, the index steadily rises, hitting 3 by 9:00 AM, and then surging to a peak of 11 between 1:00 PM and 2:00 PM. This indicates a high risk of harm from unprotected sun exposure during midday. Following the peak, the UV Index gradually declines to 4 by 5:00 PM and further decreases to 1 by 7:00 PM, emphasizing the critical importance of sun protection during the intense midday hours. It’s advisable to seek shade and wear sunscreen if you're outside during the peak period!

Average solar exposure data for the current time of the year. Actual values may vary and depend on many factors, such as cloud cover, vegetation cover, surface type, etc.
Time	UVI	Category	Time to Burn
07:00	1	low	45 min
08:00	1	low	45 min
09:00	3	moderate	30 min
10:00	5	moderate	30 min
11:00	8	very high	15 min
12:00	10	very high	15 min
13:00	11	extreme	10 min
14:00	11	extreme	10 min
15:00	9	very high	15 min
16:00	7	high	25 min
17:00	4	moderate	30 min
18:00	2	low	45 min
19:00	1	low	45 min

Monthly UV Index Trends in Princeton

As the UV Index fluctuates throughout the year, notable peaks occur from March to August, when the risk of UV exposure is highest. The months of May, June, and July see an extreme UV Index of 11, with a minimal burn time of just 10 minutes, making these months particularly hazardous for unprotected skin. April also poses a significant risk with a UV Index of 10. Conversely, from November to February, the UV Index decreases to moderate levels, particularly in December with a Index of 3. Residents and visitors should remain vigilant during the high-risk months—equipping themselves with sunscreen, protective clothing, and seeking shade during peak hours to minimize skin damage.

Monthly Maximum UV Index for Princeton, United States

The monthly maximum UV Index (UVI) represents the highest UV radiation level recorded each month in Princeton. It measures the strength of ultraviolet radiation from the sun and helps assess the risk of sunburn and UV-related health issues.

Data source: Statistical UV Index data for Princeton, based on 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.

Compare Princeton UV Index with Other United States Cities

The table above highlights how UV exposure in Princeton compares to other major locations across United States. This comparison helps travelers and residents better understand regional sun intensity and plan outdoor activities with sun safety in mind.

Princeton's solar exposure compared to other cities in United States. Generated using Copernicus Atmosphere Monitoring Service information.
	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Chicago UVI	3	4	6	8	9	10	10	9	8	6	4	2
Brooklyn UVI	3	5	6	8	10	10	9	9	8	6	4	2
New York City UVI	3	5	6	8	10	10	9	9	8	6	4	2
Los Angeles UVI	4	6	8	9	10	11	11	10	10	7	5	4
Princeton	4	6	8	10	11	11	11	10	10	7	5	3
Houston UVI	5	8	9	11	11	12	12	11	10	9	7	5