Last updated: July 2, 2025
Understanding the UV Index is crucial for residents of Wellesley, United States, where the climate can bring varying levels of sun exposure throughout the year. High UV levels can lead to sunburn, skin damage, and long-term health issues, making it essential to stay informed about daily UV forecasts. With Wellesley’s Dfa climate characterized by warm summers, the potential for elevated UV readings—peaking at 9 between noon and 1 PM—calls for extra caution. Whether you're enjoying outdoor activities or just soaking up the sun, knowing the UV Index can help you protect your skin and maintain your overall health.
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 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Wellesley | 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 |