Last updated: May 3, 2025
Understanding the UV Index is essential for residents of Groton, United States, as it provides critical information about sun exposure and its potential impact on skin health. With the UV levels rising throughout the day—peaking at 9 during midday—being aware of these fluctuations can help you prevent sunburn and long-term skin damage. Groton's Dfa climate typically sees a mix of sunny and cloudy days, leading to varying UV risks. By keeping an eye on the UV Index, you can enjoy the outdoors while safeguarding your skin against harmful rays.
From 07:00 to 09:00, the UV Index remains low, with a maximum of 1, making it a safe time for outdoor activities. However, as the day progresses, be prepared for a rise in UV exposure: by 10:00, the index reaches 4, signaling the start of increased caution. The sun peaks at 12:00, hitting an impressive 8, and climbs even higher to a maximum of 9 from 13:00 to 14:00. This is the ideal moment to seek shade or wear protective gear, as the sun's rays are at their strongest. Gradually, the index declines through the afternoon, dropping to 4 by 17:00 and falling further to a comfortable 1 by 19:00. Stay safe under the sun, especially during peak hours!
| 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 | 7 | high | 25 min |
| 16:00 | 6 | high | 25 min |
| 17:00 | 4 | moderate | 30 min |
| 18:00 | 2 | low | 45 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 |