Last updated: July 2, 2025
Understanding the UV Index is crucial for residents of Madison, United States, where sun exposure can significantly impact skin health. With summertime temperatures in the Csa climate zone often soaring, awareness of UV levels helps you prevent sunburn and reduce the long-term risks of skin damage. During peak hours, the UV Index can reach as high as 11, indicating extreme risk for harm from unprotected sun exposure. By staying informed on these daily fluctuations, you can enjoy the beautiful Wisconsin outdoors safely while taking proactive steps to protect your skin.
The UV Index throughout the day follows a predictable rise and fall, peaking at 11 around 1:00 PM. Starting at a modest 1 at 7:00 AM, it gradually escalates, reaching 10 by 12:00 PM, signaling the need for sun protection. As the afternoon progresses, the index dips from 11 to 8 by 3:00 PM, then declines further to 2 by 6:00 PM, and finally settles back at 1 by 7:00 PM. This data underscores the importance of taking precautions during the hours of peak UV exposure, particularly between 11:00 AM and 3:00 PM, when levels are highest and pose the greatest risk to skin health.
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 | 10 | very high | 15 min |
13:00 | 11 | extreme | 10 min |
14:00 | 10 | very high | 15 min |
15:00 | 8 | very high | 15 min |
16:00 | 6 | high | 25 min |
17:00 | 4 | moderate | 30 min |
18:00 | 2 | low | 45 min |
19:00 | 1 | low | 45 min |
Throughout the year, UV levels exhibit notable seasonal changes, with high-risk months occurring from April to August, where the UV Index reaches extreme levels of 11. Specifically, May, June, and July are critical periods, characterized by minimal burn times of just 10 minutes. In contrast, the winter months of January, February, November, and December display a lower UV Index, categorized as moderate (3-5), allowing up to 30 minutes of sun exposure without significant risk. As UV exposure increases, it is crucial for residents and visitors to take precautions, especially during high-risk months by wearing protective clothing, using sunscreen, and seeking shade during peak hours to effectively mitigate the risks of sunburn and long-term skin damage.
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 |
Madison | 3 | 5 | 7 | 8 | 11 | 11 | 11 | 10 | 9 | 6 | 4 | 3 |
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 |