Last updated: May 3, 2025
Understanding the UV Index is crucial for residents of Merrimac, United States, where we experience distinct seasonal shifts in our Dfb climate. Being aware of UV levels helps in preventing sunburn and promoting overall skin health, especially during the peak hours when the UV index can reach as high as 9 around noon. With outdoor activities on the rise, knowing when the risk of UV exposure is greatest—typically between 10 AM and 2 PM—can make all the difference in protecting yourself and your loved ones from harmful effects. Stay informed and enjoy the sunlight safely!
The UV Index for today presents an intriguing journey through the hours. It starts off gently at 1 at 07:00, but as the morning progresses, it climbs swiftly to 2 by 08:00 and reaches a moderate 4 at 09:00. The sun intensifies its rays further, peaking at a robust 9 between 12:00 and 13:00—a reminder to take precautions against harmful UV exposure. Following this peak, the index gradually descends, dipping to 6 at 15:00, and mellowing down to 1 by 18:00. This pattern highlights the importance of seeking shade or applying sunscreen during the midday hours when UV radiation is most potent.
| 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 | 6 | high | 25 min |
| 16:00 | 4 | moderate | 30 min |
| 17:00 | 3 | moderate | 30 min |
| 18:00 | 1 | low | 45 min |
| 19:00 | 1 | low | 45 min |
Seasonal changes in UV exposure show a notable increase from winter to summer, with the highest risk months occurring from April to August. During this period, the UV Index peaks at 10 in June, which is classified as very high, indicating a burn time of only 15 minutes. Visitors and residents are advised to take extra precautions during these months, such as wearing sunscreen, protective clothing, and sunglasses, especially between 10 AM and 4 PM, when UV radiation is strongest. As the season shifts into fall and winter, UV levels decrease, falling back to a low exposure category in January and December, with safe burn times extending to 45 minutes. However, between February and March, the UV Index returns to moderate levels, requiring vigilance to protect skin health.
UV Risk Categories
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Merrimac | 2 | 5 | 5 | 8 | 9 | 10 | 9 | 9 | 7 | 6 | 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 |