Last updated: May 3, 2025
Understanding the UV Index is crucial for residents of River Falls, United States, where the warm, humid climate (Cfa) can lead to higher sun exposure. By monitoring UV levels, you can effectively prevent sunburn and safeguard your skin health, particularly on sunny days when the index can reach a peak of 11 around midday. With UV intensity climbing as early as 9:00 AM and lasting into the afternoon, awareness of these levels empowers you to make informed decisions about sun protection and outdoor activities. Stay vigilant, as awareness of UV risks can significantly reduce the chances of long-term skin damage while enjoying the beauty of River Falls!
Throughout the day, the UV Index experiences a dramatic increase, peaking at 11 between noon and 1 PM, indicating a very high level of solar radiation. Early risers will notice a gentle start, with a UV Index of just 1 at 7 AM, gradually climbing to 4 by 9 AM. As the sun reaches its zenith, values soar to 9 at 11 AM, signaling it's time to take precautions. After the peak, the UV Index begins to decline, dropping to 10 at 2 PM, then tapering off to 3 by 5 PM and resting back down to 1 by 6 PM. Staying protected in the midday sun is crucial for skin safety during these hours!
| 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 | 7 | high | 25 min |
| 11:00 | 9 | very high | 15 min |
| 12:00 | 11 | extreme | 10 min |
| 13:00 | 11 | extreme | 10 min |
| 14:00 | 10 | 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, UV levels fluctuate, with high-risk months primarily falling between February and August. Notably, April to July feature an extreme UV Index of 11 to 12, necessitating precautions to limit sun exposure to just 10 minutes during peak hours. February and March present significant risks as well, with very high UV levels of 8 and 9, leading to burn times of only 15 minutes. To safeguard your skin, residents and visitors are advised to minimize exposure during peak sun hours, wear protective clothing, and use broad-spectrum sunscreen. As the year progresses, November and December offer lower UV levels, classified as high and moderate, respectively, allowing for longer safe exposure times of 25 to 30 minutes.
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 |
| Los Angeles UVI | 4 | 6 | 8 | 9 | 10 | 11 | 11 | 10 | 10 | 7 | 5 | 4 |
| River Falls | 5 | 8 | 9 | 11 | 11 | 11 | 12 | 11 | 10 | 8 | 6 | 4 |
| Houston UVI | 5 | 8 | 9 | 11 | 11 | 12 | 12 | 11 | 10 | 9 | 7 | 5 |