Last updated: August 1, 2025
Understanding the UV Index is crucial for residents of Madison, United States, as it plays a vital role in protecting skin health and preventing sunburn. With our climate categorized as Cfa, which implies humid summers and significant sun exposure, it's important to be aware of UV levels throughout the day. For instance, during peak hours, the UV Index can soar to 11, indicating a very high risk of harm from unprotected sun exposure. Knowing when to seek shade or apply sunscreen can make the difference in safeguarding your skin from damaging rays while enjoying the beautiful outdoor activities that Madison has to offer.
Throughout the day, the UV Index peaks dramatically, starting at a mild 1 in the early morning at 7:00 AM and 8:00 AM. As the sun climbs higher, 9:00 AM sees a moderate increase to 3, but it’s not until 10:00 AM that the UV Index hits 5, signaling a need for some sun protection. The intensity truly soars at 11:00 AM, reaching 7, and by 12:00 PM it escalates to a striking 9, before soaring to its maximum of 11 at 1:00 PM. After the zenith, the index gradually recedes to 10 at 2:00 PM, and then descends slowly: 9 at 3:00 PM, 7 at 4:00 PM, and down to 4 by 5:00 PM. The evening brings relief, as the UV Index dips to 2 at 6:00 PM and finally settles back to 1 as the sun sets at 7:00 PM. Ensure to stay protected during those peak hours!
| Time | UVI | Category | Time to Burn |
|---|---|---|---|
| 07:00 | 1 | low | 45 min |
| 08:00 | 1 | low | 45 min |
| 09:00 | 2 | low | 45 min |
| 10:00 | 4 | moderate | 30 min |
| 11:00 | 7 | high | 25 min |
| 12:00 | 9 | very high | 15 min |
| 13:00 | 10 | very high | 15 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 |
The UV Index exhibits significant seasonal variation, with high-risk months identified as April through August when the UV levels reach very high to extreme (UV Index 9-11) and burn times drop as low as 10 to 15 minutes. Particularly, June and July represent peak periods of solar exposure, emphasizing the need for heightened sun safety precautions. As visitors and residents engage in outdoor activities, it is crucial to apply sunscreen generously, wear protective clothing, and seek shade, especially during peak sun hours. Conversely, the UV Index decreases from September through December, with moderate levels in the colder months, allowing for safer outdoor experiences with less urgency for sun protective measures.
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 | 6 | 7 | 9 | 10 | 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 |