Last updated: May 3, 2025
Understanding the UV Index is crucial for residents of Janesville, United States, where varying UV levels throughout the day can significantly impact skin health and sunburn risks. The Dfa climate in Janesville brings ample sunshine, particularly during midday hours, when UV exposure can reach dangerous levels—peaking at 9 around 1 PM. By being aware of these UV indexes, you can take proactive steps to protect your skin, ensuring outdoor activities are enjoyable and safe. From applying sunscreen to seeking shade, knowing the UV levels helps safeguard your health while soaking up the sun.
As the sun rises, the UV Index begins its gradual ascent. At 7:00 AM, it starts at a modest 1, indicating minimal risk. By 8:00 AM, it rises to 2, still manageable for early risers. The intensity picks up at 9:00 AM with a 3, signaling the need for a little sunscreen. The peak arrives between 11:00 AM and 1:00 PM, where it soars to a striking 9 at 1:00 PM, which suggests strong sun protection is essential. Following this, the index slips down, recorded at 8 at 2:00 PM and 7 at 3:00 PM, offering a brief reprieve. As the afternoon fades into evening, the UV Index drops steadily, landing back at 1 by 7:00 PM. Stay informed and protect your skin during those peak hours!
| 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 | 2 | low | 45 min |
| 19:00 | 1 | low | 45 min |
As the seasons change, so do UV levels, influencing sun exposure risks throughout the year. From January to March, the UV Index is moderate, peaking at 5, where the typical burn time is 30 minutes. April through August marks the high-risk period, characterized by very high UV Index readings of 8 to 10, significantly reducing burn time to just 15 minutes. This makes April to August the months requiring the most careful sun protection measures. September to November sees a return to moderate levels, with the UV Index dropping back to 3 to 5 and a burn time of 30 minutes. Visitors and residents should prioritize sun safety during the peak summer months, utilizing sunscreen, protective clothing, and seeking shade whenever possible to minimize their risk of sunburn and long-term skin damage.
UV Risk Categories
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Janesville | 3 | 5 | 5 | 8 | 9 | 10 | 10 | 9 | 8 | 5 | 3 | 3 |
| 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 |