Last updated: July 2, 2025
Understanding the UV Index is crucial for residents of Rock Falls, United States, where sun exposure can vary drastically. Awareness of UV levels is essential not only for preventing painful sunburns, but also for safeguarding long-term skin health against potential damage. With Rock Falls’ humid continental climate (Dfa), the risk of high UV exposure peaks during the summer months, especially between 10 AM and 2 PM, when the index can reach levels as high as 10. Stay informed and take the necessary precautions to enjoy the outdoors safely!
The UV index on this particular day presents a notable trend as the sun rises and peaks. Starting at 07:00, the index is a gentle 1, gradually climbing to 2 by 08:00. The ascent continues as it reaches 4 at 09:00 and hits 6 by 10:00. Midday shines brightest, with the index soaring to a maximum of 10 at both 12:00 and 13:00, indicating a high potential for skin damage without protection. As the day progresses, values begin to dip, falling to 9 at 14:00, and then decreasing further to 8 at 15:00. By 16:00, the UV index drops to 6, and as evening approaches, it relaxes to 3 at 17:00, down to 2 by 18:00, and finally retreating to 1 at 19:00. It's a day that emphasizes the importance of sun protection during the peak 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 | 6 | high | 25 min |
| 11:00 | 8 | very high | 15 min |
| 12:00 | 10 | very high | 15 min |
| 13:00 | 10 | very high | 15 min |
| 14:00 | 9 | very high | 15 min |
| 15:00 | 8 | very high | 15 min |
| 16:00 | 6 | high | 25 min |
| 17:00 | 3 | moderate | 30 min |
| 18:00 | 2 | low | 45 min |
| 19:00 | 1 | low | 45 min |
Throughout the year, the UV Index experiences notable fluctuations, with the highest risk months occurring from March to September, when the index consistently ranges between 6 and 10. Specifically, April to August feature very high levels, with peak values reaching 10 in June and July, corresponding to a dangerously short burn time of 15 minutes. In contrast, January and December present lower UV risks, categorized as moderate to low, with corresponding burn times of 30 minutes and 45 minutes, respectively. To safeguard your skin, it is crucial for visitors and residents to adopt protective measures, especially during the peak months by using sunscreen, wearing protective clothing, and seeking shade during midday hours to reduce UV exposure effectively.
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 |
| Rock Falls | 3 | 5 | 6 | 8 | 9 | 10 | 10 | 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 |