Last updated: May 3, 2025
Understanding the UV Index is crucial for residents of Chesterfield, United States, where the climate (Dfa—humid continental) can bring intense sunshine, particularly in the summer months. Awareness of UV levels helps protect against sunburn and supports long-term skin health, as excessive exposure can lead to serious conditions like skin cancer. With midday UV Index readings peaking at a significant 10, residents should be informed about their exposure risks and adopt protective measures, ensuring they enjoy the sunny days safely while taking care of their skin.
As the sun rises, the UV Index begins its gentle climb, starting at a modest 1 at 7:00 AM and 8:00 AM. By 9:00 AM, it nudges up to a 2, signaling the day is warming up. However, the intensity ramps up dramatically around 10:00 AM, peaking at 9 by 12:00 PM. The highest alert comes at 1:00 PM and 2:00 PM with a striking 10, indicating it’s time to seek shade and protect your skin. As the afternoon unfolds, the index recedes slowly, dropping to 5 by 5:00 PM and settling down to a safe 1 by 7:00 PM. Keep in mind, during peak hours, the sun's rays are most potent—stay safe and enjoy the sunshine wisely!
| 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 | 5 | moderate | 30 min |
| 18:00 | 3 | moderate | 30 min |
| 19:00 | 1 | low | 45 min |
Throughout the year, seasonal changes in UV Index levels highlight varying risks associated with sun exposure. From January to February, UV levels remain moderate, with burn times of 30 minutes, making it a relatively safer period for outdoor activities. However, as March approaches, the UV Index escalates to 6, indicating higher caution is needed. The spring and summer months show a significant increase, peaking in June with an extreme UV Index of 11, where burn time reduces to just 10 minutes. High-risk months include April through August, with very high to extreme levels; visitors and residents should take extra precautions, like wearing sunscreen, hats, and protective clothing during these months. As the year progresses into October and November, UV levels decrease, returning to moderate levels by December, providing a safer environment for outdoor enjoyment. It’s essential for everyone to stay informed about UV levels and adjust their sun safety practices accordingly.
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 |
| Chesterfield | 3 | 5 | 6 | 9 | 10 | 11 | 10 | 9 | 8 | 6 | 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 |