Last updated: June 2, 2025
Understanding the UV Index is crucial for residents of Dedham, Massachusetts, as it serves as a vital tool for protecting skin health and preventing sunburn. With Dedham’s Dfb climate bringing a mix of warm summers and cold winters, the potential for UV exposure can fluctuate throughout the year. However, during peak hours, particularly from 10 AM to 2 PM, it’s imperative to be aware of rising UV levels—reaching as high as 10 on sunny days. By keeping track of the UV Index, Dedham residents can enjoy the outdoors safely, minimizing the risk of skin damage while advocating for a healthier lifestyle.
Throughout the day, the UV Index sees a dynamic escalation, peaking at 10 between 12:00 PM and 1:00 PM, signaling the most intense sun exposure. Early morning hours remain mild with a maximum of 1 at 7:00 AM, gradually escalating to 3 by 8:00 AM. As the sun climbs higher, it reaches 7 at 10:00 AM and then surges to 9 by 11:00 AM. The afternoon delivers a slight decline, with 9 at 1:00 PM, tapering down to 7 by 3:00 PM. The evening sees the index diminishing steadily, dropping back to 3 at 5:00 PM, and returning to 1 by 6:00 PM, reminding us of the importance of sun protection during the peak hours.
| Time | UVI | Category | Time to Burn |
|---|---|---|---|
| 07:00 | 1 | low | 45 min |
| 08:00 | 3 | moderate | 30 min |
| 09:00 | 5 | moderate | 30 min |
| 10:00 | 7 | high | 25 min |
| 11:00 | 9 | very high | 15 min |
| 12:00 | 10 | 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 |
The UV Index exhibits notable seasonal variations, with the highest levels occurring during the summer months. May and June stand out as the months with the highest risk, featuring very high UV Index values of 9 and 10, respectively, allowing for a burn time as short as 15 minutes. From April to August, the UV exposure is particularly concerning, with values of 7 or more, categorizing these months as high to very high risk for skin damage. Visitors and residents are strongly advised to take precautions during these months, such as wearing protective clothing, using broad-spectrum sunscreen, and seeking shade, especially during midday hours when UV radiation is at its peak. As we transition into fall and winter, the UV Index decreases, becoming low in January and December, providing a reprieve from intense sun exposure and longer burn times of 45 minutes.
UV Risk Categories
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Dedham | 2 | 4 | 5 | 7 | 9 | 10 | 8 | 8 | 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 |