Last updated: July 2, 2025
In Groton, United States, understanding the UV Index is crucial for ensuring skin health and preventing sunburns. With the region's Dfa climate, residents face various UV exposure risks, especially during the peak hours between 11 AM and 3 PM, when values can soar to 9. Awareness of these UV levels not only helps individuals protect themselves from harmful rays but also encourages a proactive approach to enjoying the sun safely. Stay informed to make the most of Groton’s sunny days while safeguarding your skin!
As the sun rises, the UV Index gradually climbs, starting at a low of 1 by 07:00 and 08:00. The real leap begins at 09:00, where it reaches 3, escalating to 4 by 10:00. As noon approaches, the UV Index peaks at an impressive 9 from 13:00 to 14:00, making it crucial to take protective measures during those hours. Afterward, it begins to taper off, dropping to 6 by 16:00, and further declining through the late afternoon and evening, eventually falling back to 1 by 19:00. For those venturing outdoors, staying vigilant to the UV levels during the midday hours is essential for skin protection!
| 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 | 4 | moderate | 30 min |
| 11:00 | 6 | high | 25 min |
| 12:00 | 8 | very high | 15 min |
| 13:00 | 9 | very high | 15 min |
| 14:00 | 9 | very high | 15 min |
| 15:00 | 8 | very high | 15 min |
| 16:00 | 6 | high | 25 min |
| 17:00 | 4 | moderate | 30 min |
| 18:00 | 3 | moderate | 30 min |
| 19:00 | 1 | low | 45 min |
As the seasons change, so do the UV levels. January starts off with a moderate UV Index of 3, allowing for a burn time of 30 minutes before protection is needed. As we move into February and March, the UV Index remains at 5, still in the moderate category. However, starting in April, UV exposure escalates with an Index of 7, indicating a high risk of harm, with a reduced burn time of 25 minutes. The peak months for UV exposure are May through August, where the Index reaches a very high level of 9 to 10, allowing only 15 minutes of unprotected sun exposure. September and October see a decrease back to high and moderate levels respectively, with UV Index readings of 7 and 5, and burn times of 25 and 30 minutes. The year rounds out with lower risks in November and December, where the UV Index drops to 3 and 2, with burn times extending to 30 and 45 minutes. It is crucial for visitors and residents to prioritize sun safety, especially during the high-risk months of April to August by applying sunscreen, wearing protective clothing, and seeking shade when necessary.
UV Risk Categories
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Groton | 3 | 5 | 5 | 7 | 9 | 10 | 9 | 9 | 7 | 5 | 3 | 2 |
| 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 |