Last updated: May 3, 2025
Understanding the UV Index is crucial for residents of Heidelberg, United States, especially during the sunnier months when UV levels can soar. Staying aware of these levels helps in preventing sunburn and promoting long-term skin health, as even brief exposure to high UV radiation can cause skin damage. With Heidelberg's Cfa climate, characterized by warm summers, the risk of overexposure rises significantly around midday, peaking with levels reaching as high as 12. By keeping an eye on the UV Index, you can better protect yourself and enjoy the sunny days safely.
The day begins gently with a UV Index of 1 at both 07:00 and 08:00, indicating minimal sun exposure. However, as the clock strikes 09:00, the index rises to 3, signifying a gradual increase in UV intensity. By 10:00, it reaches 5, and the sun takes center stage at 11:00 with a striking 8. The peak arrives at 12:00, soaring to an impressive 10, and continues to climb, hitting its pinnacle with a dazzling 12 at 13:00. As the afternoon unfolds, values begin a slow descent: 11 at 14:00, 10 at 15:00, and then dropping to 7 by 16:00. The evening brings relief, with the index tapering down to 4 at 17:00, 2 at 18:00, and finally returning to a safe 1 by 19:00. Remember to stay protected during those peak hours!
| 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 | 5 | moderate | 30 min |
| 11:00 | 8 | very high | 15 min |
| 12:00 | 10 | very high | 15 min |
| 13:00 | 12 | extreme | 10 min |
| 14:00 | 11 | extreme | 10 min |
| 15:00 | 10 | very high | 15 min |
| 16:00 | 7 | high | 25 min |
| 17:00 | 4 | moderate | 30 min |
| 18:00 | 2 | low | 45 min |
| 19:00 | 1 | low | 45 min |
Throughout the year, the UV Index fluctuates significantly, with high-risk months typically falling between February and September. During this time, values soar to extreme levels of 12, especially in May through August, where the recommended burn time is only 10 minutes. In March and April, the index remains in the very high to extreme categories, with burn times decreasing to just 10-15 minutes. As summer gradually transitions into fall, the UV Index begins to decline, allowing for slightly longer burn times in October at 15 minutes, but still indicating a very high risk. For winter months, January, November, and December maintain a high exposure category but extend burn times back to 25 minutes. Visitors and residents should remain vigilant, particularly during the peak UV months, taking proactive measures such as wearing sunscreen, protective clothing, and seeking shade during peak hours to mitigate the risks associated with intense sun exposure.
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 |
| Houston UVI | 5 | 8 | 9 | 11 | 11 | 12 | 12 | 11 | 10 | 9 | 7 | 5 |
| Heidelberg | 6 | 9 | 10 | 11 | 12 | 12 | 12 | 12 | 11 | 9 | 7 | 6 |