Last updated: May 3, 2025
Understanding the UV Index is crucial for residents of Napoleon, United States, especially given the region's Dfb climate that features distinct seasons and varying levels of sun exposure. Awareness of UV levels not only aids in preventing sunburn but also plays a vital role in maintaining long-term skin health. During peak hours, particularly between noon and 3 PM, UV Index values can reach as high as 9, indicating a very high risk of harm from unprotected sun exposure. By staying informed and taking protective measures, you can enjoy the sunny days in Napoleon while safeguarding your skin from harmful UV rays.
Starting from 07:00 AM, the UV Index remains low at 1, perfect for a morning stroll. As the sun climbs higher, the intensity gradually increases: reaching 3 by 09:00 AM and then escalating to 4 at 10:00 AM. The peak intensity occurs at 01:00 PM, with a striking UV Index of 9, suggesting it's vital to seek shade or apply sunscreen during this hour. The afternoon sees a slight decline, with values of 8 at 03:00 PM and 6 by 04:00 PM. As the day winds down, the UV Index drops back to 4 at 05:00 PM, and then gently falls to 2 by 06:00 PM, before settling back at 1 near sunset. It's a day to stay sun-smart!
| Time | UVI | Category | Time to Burn |
|---|---|---|---|
| 07:00 | 1 | low | 45 min |
| 08:00 | 1 | low | 45 min |
| 09:00 | 3 | moderate | 30 min |
| 10:00 | 4 | moderate | 30 min |
| 11:00 | 6 | high | 25 min |
| 12:00 | 8 | very high | 15 min |
| 13:00 | 9 | 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 | 4 | moderate | 30 min |
| 18:00 | 2 | low | 45 min |
| 19:00 | 1 | low | 45 min |
As the seasons change, so do the UV Index levels, which significantly affect sun exposure risk. High-risk months for UV exposure include April through August, where the UV Index reaches very high levels of 9 or 10, resulting in a burn time as short as 15 minutes. Notably, July often peaks at an index of 10, highlighting the critical need for protection during summer months. In contrast, the winter months from December to February display moderate to low UV levels, with safer exposure times of 30 to 45 minutes. To protect yourself, residents and visitors should prioritize sun safety measures—such as using sunscreen, wearing protective clothing, and limiting exposure during peak sunlight hours—in the high-risk months, while enjoying longer sun exposure in the winter with proper precautions.
UV Risk Categories
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Napoleon | 3 | 5 | 5 | 9 | 9 | 10 | 9 | 9 | 7 | 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 |