Last updated: July 2, 2025
Understanding the UV Index is vital for residents and visitors of Williamstown, United States, where the climate offers both beautiful sunny days and potential risks of overexposure to ultraviolet radiation. With typical UV Index levels peaking at 10 during midday, awareness of these UV ratings is essential for preventing sunburn and protecting skin health. As Williamstown experiences a Cfa climate, characterized by warm summers, it's crucial to recognize when UV levels are at their highest, ensuring that you take necessary precautions to enjoy the sun safely.
The UV Index rises swiftly throughout the morning, starting from a low of 1 at 07:00 and climbing steadily to reach its peak of 10 at 13:00. As the sun reaches its zenith, the index hits 9 at 12:00, a clear reminder of the intense midday sun. After this high, the UV levels gradually decrease; by 15:00, they drop to 8 and continue to soften to 3 by 17:00, before safely settling back to a 1 at 19:00. It's essential to stay protected during those peak hours, particularly between 11:00 and 14:00, when the sun’s rays can be most dangerous. Remember to apply sunscreen and wear protective clothing to keep your skin safe while enjoying the outdoors!
Time | UVI | Category | Time to Burn |
---|---|---|---|
07:00 | 1 | low | 45 min |
08:00 | 2 | low | 45 min |
09:00 | 3 | moderate | 30 min |
10:00 | 5 | moderate | 30 min |
11:00 | 8 | very high | 15 min |
12:00 | 9 | very high | 15 min |
13:00 | 10 | very high | 15 min |
14:00 | 9 | very high | 15 min |
15:00 | 8 | very high | 15 min |
16:00 | 6 | high | 25 min |
17:00 | 3 | moderate | 30 min |
18:00 | 2 | low | 45 min |
19:00 | 1 | low | 45 min |
Throughout the year, UV exposure varies significantly, peaking during late spring and summer months. High-risk months for UV exposure are April through September, where the UV Index frequently reaches levels classified as very high; particularly notable are May, June, and July, when it consistently hits a maximum of 10. Visitors and residents are advised to take precautions during these months, with burn times dramatically reduced to as little as 15 minutes. In contrast, January, February, and November present moderate UV levels, and December has a low index, making sun safety measures less critical during these months. To protect against skin damage, it is essential to wear sunscreen, seek shade, and wear protective clothing, especially between peak months of April and September.
UV Risk Categories
Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
---|---|---|---|---|---|---|---|---|---|---|---|---|
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 |
Williamstown | 3 | 5 | 6 | 9 | 10 | 10 | 10 | 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 |