UV Index in Princeton, United States

Last updated: July 2, 2025

Understanding the UV Index in Princeton, United States, is essential for safeguarding your skin and overall health. With the town's Cfa climate, residents and visitors alike can experience varying UV exposure risks throughout the day, particularly during peak hours. By being aware of the UV levels, you can take necessary precautions against sunburn and long-term skin damage, especially when the index reaches a high of 10 during midday. Whether you’re enjoying the outdoors or just running errands, staying informed about the UV Index helps you protect your skin from harmful rays and enjoy a safer, healthier lifestyle in Princeton.

Hourly UV Index in Princeton

The UV Index throughout the day showcases a dynamic pattern of sun exposure, peaking during the afternoon. At 07:00, the index starts low at 1, gradually increasing as the sun rises. By 10:00, it reaches 6, signaling a rise in sun intensity, culminating in a striking 10 from 12:00 to 13:00, indicating a high risk of harm from unprotected sun exposure. As the day progresses, the UV Index declines, dropping to 3 by 17:00, and steadily returning to 1 by 19:00. This data highlights the importance of sun protection, especially during midday when the UV Index is at its highest.

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	2	low	45 min
09:00	4	moderate	30 min
10:00	6	high	25 min
11:00	8	very high	15 min
12:00	10	very high	15 min
13:00	10	very high	15 min
14:00	9	very high	15 min
15:00	8	very high	15 min
16:00	5	moderate	30 min
17:00	3	moderate	30 min
18:00	2	low	45 min
19:00	1	low	45 min

Monthly UV Index Trends in Princeton

The UV Index exhibits significant seasonal changes, with the highest levels occurring from March to September. Visitors and residents should be particularly cautious during the high-risk months of April, May, June, July, August, and September, when UV exposure reaches very high to extreme levels, with burn times as low as 10 to 15 minutes. In contrast, January, February, November, and December experience moderate UV levels, allowing for longer safe exposure times of 30 minutes. To minimize the risk of skin damage, it is advised that individuals wear appropriate sun protection, such as sunscreen, hats, and protective clothing, especially during peak UV hours from 10 AM to 4 PM.

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
Princeton	3	5	7	10	10	11	10	9	9	7	4	3
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