Last updated: July 2, 2025
Understanding the UV Index in Merrimack, United States, is crucial for safeguarding your skin and overall health. As residents enjoy the beautiful seasonal changes typical of the Dfb climate zone, it’s essential to be mindful of potential UV exposure, especially during peak hours when the index can reach as high as 9 between noon and 1 PM. By staying informed about UV levels, you can take proactive steps to prevent sunburns, reduce the risk of skin damage, and maintain your skin's health. With Merrimack's changing climate, knowing when to seek shade or apply sunscreen can make all the difference in your outdoor enjoyment.
The UV Index today presents a notable climb as the sun ascends, peaking at 9 around noon and early afternoon, signaling very high sun exposure risk. Starting gently at 1 by 7 AM, the index rises steadily, reaching 6 by 10 AM and then surging to its maximum of 9 between 12 PM and 1 PM. Early afternoon brings a slight decline to 8 at 2 PM, followed by a gradual decrease through the later hours, settling back to 1 by 7 PM. With this trajectory, it's crucial to take precautions during the peak hours of 11 AM to 1 PM, ensuring skin protection against harmful UV rays. Stay safe and enjoy the sun wisely!
| 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 | 2 | low | 45 min |
| 19:00 | 1 | low | 45 min |
The seasonal UV Index shows significant variation, with high-risk months occurring from April through August when the UV Index reaches levels classified as very high. During these months, exposure times drop to just 15 minutes, emphasizing the need for protective measures. In April, the UV Index escalates to 8, peaking at 10 in June before slightly declining to 9 in July and August. As fall approaches, the risk decreases; however, September and October still pose a high risk with UV Index values of 7 and 6, respectively. For visitors and residents, it is crucial to take precautions, such as wearing sunscreen, hats, and protective clothing, especially during peak hours in these high-risk months. January through March and November through December present lower risks, with UV levels generally moderate to low; these months require less stringent sun protection but still warrant caution.
UV Risk Categories
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Merrimack | 3 | 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 |