UV Index in Princeton, United States

Last updated: July 2, 2025

In Princeton, United States, being aware of the UV Index is essential for protecting your skin health and preventing painful sunburns. Understanding UV levels helps you make informed decisions about sun exposure, especially during summer months when the risk of skin damage is higher. With a climate characterized as Am, residents often experience high UV exposure, especially between 11 AM and 2 PM, when the UV Index peaks at a soaring 12. By staying informed about local UV conditions, you can enjoy the outdoors while safeguarding your skin from harmful ultraviolet rays.

Hourly UV Index in Princeton

As the sun rises, the UV Index starts off low at a manageable 1 from 07:00 to 08:00. However, things heat up quickly as we move into the late morning; by 10:00, it spikes to 5, reaching 8 at 11:00. The peak intensity occurs at 12:00, with an impressive index of 11, closely followed by 12 at 13:00 and 14:00—the sun is at its strongest! A gradual decrease follows, dropping to 10 by 15:00 and continuing down to 4 at 17:00. As the day winds down, the index relaxes further to 2 at 18:00 and returns to a safe 1 by 19:00. It's clear that today's UV risk peaks around midday, so remember to stay protected during those exposed hours!

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	11	extreme	10 min
13:00	12	extreme	10 min
14:00	12	extreme	10 min
15:00	10	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

Throughout the year, UV levels fluctuate significantly, with the highest risk occurring from February to September. The UV Index peaks in June at 13, classified as extreme, with a burn time of only 10 minutes. Other high-risk months include April and May, also rated as extreme, along with July and August. Visitors and residents should take precautions during these months, such as wearing sunscreen, protective clothing, and seeking shade to minimize exposure. October and November still present very high risks, while January and December lower to high levels, where burn time increases to 25 minutes. Staying informed about UV conditions is essential for safety year-round.

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
Houston UVI	5	8	9	11	11	12	12	11	10	9	7	5
Princeton	6	9	10	12	12	13	12	12	11	10	8	6