Last updated: June 2, 2025
In Williamstown, United States, staying informed about the UV Index is essential for maintaining skin health and preventing sunburn. Understanding the daily fluctuations in UV levels empowers residents to take proactive measures, especially during peak hours when the index can reach a high of 10 between noon and 1 PM. With a Cfa climate characterized by hot summers and moderate sun exposure, it's crucial for locals and visitors alike to be aware of their surroundings and safeguard against harmful UV rays. By being mindful of the UV Index, you can enjoy the beautiful outdoors while protecting your skin for years to come.
As the sun climbs higher in the sky, the UV Index rises dramatically throughout the morning and into the afternoon. Starting at a modest 1 at 7:00 AM, the levels gradually escalate, reaching 2 by 8:00 AM and hitting 4 by 9:00 AM. The intensity peaks at 10 around 1:00 PM, marking the most critical time for sun safety. From this peak, the index gently descends, dropping to 9 at 2:00 PM and then tapering down to 3 by 5:00 PM. As evening approaches, the UV Index diminishes to a gentle 1 by 7:00 PM. It's essential to stay protected during the mid-day heat, especially when the UV levels are at their highest.
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 | 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 |