Last updated: June 2, 2025
Understanding the UV Index is crucial for residents of Petersburg, United States, where the warm Cfa climate brings ample sunshine and potential skin health risks. With UV levels peaking at 11 around noon, awareness of these daily fluctuations is essential for preventing sunburn and protecting your skin. Whether basking in the sun or enjoying outdoor activities, knowing the UV Index can help you make informed choices about sun protection, ensuring you enjoy Petersburg's beautiful weather safely.
The UV Index for the day presents a fascinating variation as the sun climbs higher in the sky. Starting from a gentle 1 at 07:00, the intensity gradually escalates, reaching a moderate 4 by 09:00. The peak hits at 12:00 and 13:00, soaring to an intense 11, indicating a significant risk of harm from unprotected sun exposure. As the afternoon unfolds, the index begins to decline, tapering to 8 at 15:00, and by the evening, it plummets back to a 1 by 18:00. This data serves as a reminder to stay vigilant about sun safety during those peak hours when UV exposure is at its highest!
| 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 | 8 | very high | 15 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 |
The UV Index exhibits notable seasonal variation, with the most intense sun exposure occurring in the summer months of June and July, where the index reaches 11—classified as extreme—allowing for a burn time of just 10 minutes. Following this peak, UV levels remain high through August and September, before gradually declining into the fall and winter months. High-risk months for sun exposure include March through September, particularly April, May, June, and July, where the index consistently registers in the very high to extreme categories. Visitors and residents are advised to take precautionary measures during these periods, such as applying sunscreen of at least SPF 30, wearing protective clothing, and seeking shade during midday hours. Conversely, from November to February, UV levels drop significantly, resulting in lower risk factors for sunburn.
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 |
| Petersburg | 4 | 6 | 8 | 10 | 10 | 11 | 11 | 10 | 9 | 7 | 5 | 3 |
| Houston UVI | 5 | 8 | 9 | 11 | 11 | 12 | 12 | 11 | 10 | 9 | 7 | 5 |