UV Index in Princeton, United States

Last updated: June 2, 2025

In Princeton, United States, being aware of the UV Index is crucial for safeguarding your skin and overall health. With typical UV exposure risks peaking during the midday hours, understanding the UV levels can help you take preventive measures against sunburn and long-term skin damage. Princeton's humid subtropical climate brings plenty of sunny days, which can lead to high UV levels—reaching an intensity of 12 at noon, indicating that it's important to wear sunscreen, hats, and protective clothing when outdoors. Stay informed and enjoy the sunshine safely!

Hourly UV Index in Princeton

As the sun rises on this bright day, the UV Index starts off relatively low, peaking at just 1 at both 7:00 AM and 8:00 AM. However, by 9:00 AM, it jumps to 3, signaling an increase in UV exposure. The intensity escalates quickly, reaching a notable 6 by 10:00 AM. The real intensity hits its peak at 12:00 PM, when the UV Index soars to a striking 12, followed closely by a high of 13 at 1:00 PM. Over the next few hours, the index gradually diminishes, but still remains significant with 10 at 3:00 PM and 7 by 4:00 PM. As evening approaches, the levels continue to decline, returning to 1 once dusk settles in at 7:00 PM. Be sure to protect your skin!

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	6	high	25 min
11:00	9	very high	15 min
12:00	12	extreme	10 min
13:00	13	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