Last updated: May 3, 2025
Understanding the UV Index is crucial for residents and visitors in Charleston, United States, where sunny skies can lead to increased exposure to harmful ultraviolet rays. Being aware of UV levels helps in preventing sunburns and protecting skin health, ensuring you enjoy your time outdoors without the risk of damage. With Charleston's humid subtropical climate, daily UV exposure can reach high levels, particularly during midday, peaking at a significant UV Index of 10. Stay informed to safeguard your skin and make the most of your time in this beautiful city!
At dawn, the UV Index starts at a mild 1 at 7:00 AM, gradually rising to 2 by 8:00 AM. As the day progresses, from 9:00 AM with a 4 to a peak at 12:00 PM, the index hits an intense 10. This high level persists until 2:00 PM, urging outdoor enthusiasts to seek shade and protect their skin. The afternoon sees a descent, dipping to 8 at 3:00 PM and dropping further to 3 by 5:00 PM. Finally, as the sun sets, the UV Index returns to a safe 1 by 6:00 PM, making the evening hours perfect for outdoor activities without sun concerns.
| 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 | 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 |
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 |
| Charleston | 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 |