Last updated: August 1, 2025
Understanding the UV Index is crucial for the residents of Sun Prairie, United States, where sunny days can quickly lead to increased UV exposure. With a climate characterized by hot summers and cold winters, awareness of UV levels becomes essential for protecting your skin from harmful rays that can cause sunburn and long-term health issues. Throughout the day in Sun Prairie, UV indexes can peak at a high of 10 around midday, emphasizing the need for vigilance, especially when spending time outdoors. By staying informed about UV levels, you can enjoy the beautiful Wisconsin weather while ensuring your skin remains healthy and protected.
As the day unfolds, the UV Index experiences a dramatic rise, peaking at an intense 10 around 1 PM, signaling the highest level of harmful UV radiation. Early morning hours start gently, with a maximum of 1 at 7 AM, gradually increasing to a moderate 4 by 9 AM. The ascent continues steadily, reaching a notable 8 between 11 AM and 12 PM before soaring to its zenith. After this peak, the index begins to wane, declining to 5 by 4 PM and dropping further to a safe 1 by 7 PM. It’s vital to stay protected during the peak hours of 11 AM to 3 PM to enjoy the sunshine without compromising skin health.
| 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 | 7 | high | 25 min |
| 12:00 | 8 | 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 | 1 | low | 45 min |
| 19:00 | 1 | low | 45 min |
Throughout the year, the UV Index shows significant seasonal changes that impact sun safety for residents and visitors. From April to September, the UV Index peaks, reaching levels as high as 10 in the summer months of June and July. This indicates a very high exposure category, with a reduced burn time of only 15 minutes during these months. Conversely, during the winter months of December through February, the UV Index is considerably lower, ranging from 2 to 4, with a burn time of 30 to 45 minutes. Therefore, visitors and residents should be especially cautious during the high-risk months of April to September, and take appropriate protective measures, such as wearing sunscreen, protective clothing, and seeking shade, to minimize their risk of UV exposure.
UV Risk Categories
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sun Prairie | 3 | 4 | 5 | 8 | 9 | 10 | 10 | 9 | 8 | 5 | 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 |