UV Index in Groton, United States

Last updated: July 2, 2025

In Groton, United States, being aware of the UV Index is essential for safeguarding your skin and overall health. Understanding UV levels can help you take proactive steps to prevent sunburn and long-term damage, making it a critical aspect of outdoor activities, especially during the sunniest hours of the day. With a Dfb climate characterized by warm summers and cold winters, Groton experiences varying UV exposure, reaching its peak at a high of 10 between 1 PM and 2 PM. Recognizing these UV trends not only enhances your sun safety but also promotes better skin health throughout the seasons.

Hourly UV Index in Groton

The UV Index throughout the day presents a dynamic picture of solar intensity. Morning hours start gently, with a low of 1 at 07:00 and a gradual rise to 2 by 08:00. As the sun climbs higher, the index peaks at a striking 10 at 13:00, signaling the most intense sun exposure, making it prudent for sun protection. From 14:00, the UV Index begins to dip, yet remains significant at 9, before tapering off to 5 by 16:00. As evening approaches, the levels drop further, resting at 1 by 19:00. This hourly progression showcases the importance of sun safety measures, particularly during those midday hours when the UV radiation 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	3	moderate	30 min
10:00	5	moderate	30 min
11:00	7	high	25 min
12:00	9	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 Groton

During the year, the UV Index shows significant seasonal variations, with peak levels reached in late spring and summer. The highest risk months are from April to September, where the UV Index often exceeds 8, categorized as very high. Particularly, May through August sees a consistent UV Index of 10, indicating a burn time of just 15 minutes for unprotected skin. In contrast, January, February, November, and December have much lower UV levels, with burn times spiking up to 45 minutes during December. To protect against skin damage, visitors and residents should take extra precautions during the high-risk months by wearing sunscreen with high SPF, protective clothing, and seeking shade, especially during peak hours.

Monthly Maximum UV Index for Groton, United States

The monthly maximum UV Index (UVI) represents the highest UV radiation level recorded each month in Groton. 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 Groton, 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 Groton UV Index with Other United States Cities

The table above highlights how UV exposure in Groton 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.

Groton'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
Groton	3	4	6	8	10	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