Last updated: July 2, 2025
Understanding the UV Index is crucial for residents of Somerville, United States, as it serves as an essential guide to sun safety and skin health. In a region characterized by a Dfb climate, the UV levels can rise significantly, especially during the midday hours when they peak at 9, indicating a high risk of harm from unprotected sun exposure. Being aware of these levels helps prevent sunburn and long-term skin damage, making it important for everyone to check the UV Index daily. Whether you're enjoying a stroll in the park or running errands, being informed about UV risks can help you protect your skin and enjoy the sunshine responsibly.
The UV Index reveals a dynamic pattern throughout the day, starting at a mild 1 at 07:00 and steadily rising as the sun reaches its peak. By 10:00, it escalates to a moderate 6, reaching 8 at 11:00 and peaking at an intense 9 from 12:00 to 13:00. This period signifies the greatest caution for sun exposure, making it essential to seek shade and wear protective clothing. As the afternoon unfolds, the index begins to dip, dropping to 8 at 14:00, then declining further to 7 by 15:00, and tapering down to 1 by 19:00. Overall, it’s a day that encourages sun safety awareness, particularly during the midday hours when UV radiation is at its strongest.
| 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 | 9 | very high | 15 min |
| 13:00 | 9 | very high | 15 min |
| 14:00 | 8 | very high | 15 min |
| 15:00 | 7 | high | 25 min |
| 16:00 | 5 | moderate | 30 min |
| 17:00 | 3 | moderate | 30 min |
| 18:00 | 1 | low | 45 min |
| 19:00 | 1 | low | 45 min |
Throughout the year, the UV Index demonstrates significant seasonal changes, particularly peaking in the summer months. Notably, April to August presents the highest risk for UV exposure, with May and June reaching a maximum of 10, categorized as very high risk, where the burn time drops to just 15 minutes. Visitors and residents should be especially cautious during these months, ensuring they wear protective clothing, apply broad-spectrum sunscreen, and seek shade during peak hours. Conversely, the UV Index declines from September onwards, dropping to a low of 2 in December, which indicates reduced risk. It is advisable to remain vigilant year-round, adapting sun safety practices according to the current UV levels to ensure optimal skin protection.
UV Risk Categories
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Somerville | 3 | 5 | 5 | 8 | 9 | 10 | 9 | 9 | 7 | 6 | 4 | 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 |