Last updated: August 1, 2025
Understanding the UV Index is crucial for residents of La Crosse, where sunny days are as plentiful as the beautiful river views. With UV levels peaking at a striking 11 during the summer months, awareness of these figures is essential for sunburn prevention and maintaining skin health. La Crosse's humid subtropical climate brings plenty of sunshine, making it imperative to stay informed about daily UV exposure risks. By monitoring this vital index, you can enjoy the outdoors safely while protecting your skin from harmful rays that can lead to long-term damage.
At sunrise, the UV Index starts at a gentle 1 by 07:00, perfect for early risers enjoying the morning light. As the day progresses, it gradually climbs, reaching a moderate 3 by 09:00 and peaking at an intense 11 around 13:00 and 14:00. During these midday hours, the sun's rays are at their most powerful, making it crucial to seek shade or wear protective gear. Post-peak, the index begins to decline, descending to 5 by 17:00 and tapering off to 1 again by 19:00. This dynamic pattern highlights the importance of staying vigilant about sun protection, especially during 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 | 9 | very high | 15 min |
| 16:00 | 7 | 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 index levels vary significantly, with high-risk months occurring from March to August. The UV Index peaks in June and July at level 11, classified as extreme, indicating a burn time of just 10 minutes. During this period, it is crucial for visitors and residents to take extra precautions, such as wearing broad-spectrum sunscreen, protective clothing, and seeking shade during peak sun hours. As we transition into the fall months, the UV Index drops to 9 in September and October, remaining high yet manageable, while the winter months of December through February feature a lower UV Index, ranging from 3 to 5, which presents a more moderate risk. Nonetheless, it is always advisable to remain aware of UV levels year-round and take appropriate sun safety measures when necessary.
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 |
| La Crosse | 4 | 5 | 7 | 9 | 10 | 11 | 11 | 10 | 9 | 7 | 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 |