Last updated: May 3, 2025
Understanding the UV Index is crucial for residents and visitors of Charleston, South Carolina, as it directly impacts your skin health and sunburn prevention efforts. With a humid subtropical (Cfa) climate, Charleston experiences high levels of ultraviolet radiation, particularly during the peak hours between 11 AM and 3 PM, when the UV Index can soar to a maximum of 11. By being aware of the UV levels, you can take necessary precautions to protect your skin from harmful rays and enjoy the sunny outdoors safely. Remember, a little knowledge goes a long way in safeguarding your health while soaking up Charleston's beautiful sunshine!
Today’s UV Index tells a compelling story of the sun's intensity throughout the day. Starting off gently at 1 at 7:00 AM, it gradually picks up, reaching 2 by 8:00 AM. As the day warms up, it surges to a moderate 4 by 9:00 AM and hits 6 at 10:00 AM. The sun shines fiercest at 12:00 PM, where the UV Index peaks at an impressive 10, nudging even higher to 11 at 1:00 PM. After lunchtime, we see a steady decline: it dips to 10 at 2:00 PM, falls to 8 by 3:00 PM, and continues its descent to 5 at 4:00 PM. As evening approaches, the index drops significantly, ending the day with a cozy 1 by 7:00 PM. Remember to take precautions during the peak hours for skin safety!
| 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 | 9 | very high | 15 min |
| 12:00 | 10 | very high | 15 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 | 2 | low | 45 min |
| 19:00 | 1 | low | 45 min |
The UV Index experiences significant seasonal variation, peaking in the spring and summer months. From April to September, the UV Index reaches very high levels, particularly in May and June, when it hits an extreme rating of 11. The high-risk months for UV exposure are April through September, with the lowest burn time of just 10 minutes occurring in May and June. As such, it's crucial for visitors and residents to take precautions during these months by wearing protective clothing, applying sunscreen regularly, and seeking shade, especially between 10 AM and 4 PM. In the fall and winter, the UV Index decreases to moderate levels, with safer exposure times returning. However, awareness is still essential year-round to prevent skin damage.
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 | 6 | 7 | 10 | 11 | 11 | 10 | 10 | 9 | 7 | 5 | 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 |