Last updated: June 2, 2025
Staying informed about the UV Index is crucial for residents and visitors in Bonn, Germany, as it plays a significant role in protecting your skin and overall health. Understanding UV levels can help prevent sunburn and long-term skin damage, allowing you to enjoy the beautiful outdoor activities this vibrant city has to offer. With Bonn’s Cfb climate, characterized by mild winters and warm summers, UV exposure can vary throughout the day. During peak hours, particularly around noon, the UV Index can rise to 8, signaling the need for protective measures to keep your skin safe. Whether you’re strolling along the Rhine or exploring the historic sites, being UV-aware ensures your adventures are as safe as they are enjoyable!
At sunrise, the UV Index starts at a modest 1 by 7:00 AM, gradually climbing to 2 by 8:00 AM. The intensity picks up rapidly, reaching a peak of 8 between 12:00 PM and 2:00 PM, signaling the sun's strength at midday. As the afternoon progresses, the index gently declines; by 5:00 PM, it drops to 4, and further to 3 by 6:00 PM. By the time the sun begins to set at 7:00 PM, the UV Index falls back to a low 1. This pattern beautifully illustrates the sun's journey, reminding us to stay protected during the day's sunniest hours!
| Time | UVI | Category | Time to Burn |
|---|---|---|---|
| 07:00 | 1 | low | 45 min |
| 08:00 | 2 | low | 45 min |
| 09:00 | 3 | moderate | 30 min |
| 10:00 | 4 | moderate | 30 min |
| 11:00 | 6 | high | 25 min |
| 12:00 | 8 | very high | 15 min |
| 13:00 | 8 | very high | 15 min |
| 14:00 | 8 | very high | 15 min |
| 15:00 | 7 | high | 25 min |
| 16:00 | 6 | high | 25 min |
| 17:00 | 4 | moderate | 30 min |
| 18:00 | 3 | moderate | 30 min |
| 19:00 | 1 | low | 45 min |
Throughout the year, UV Index values fluctuate significantly, indicating varying levels of sun exposure risk. The high-risk months are from May to August, where the UV Index reaches its peak at 7-8, classifying them as high to very high exposure. Specifically, June and July present the greatest risk, with a burn time of only 15 minutes. In contrast, the winter months (January, February, November, and December) show a low exposure category with UV Index values of 1-2, allowing for longer safe sun exposure (up to 45 minutes). To ensure safety, it is advisable for visitors and residents to take protective measures during the high UV months, such as wearing sunscreen, protective clothing, and seeking shade, especially during midday hours.
UV Risk Categories
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Hamburg UVI | 1 | 2 | 3 | 5 | 7 | 8 | 7 | 7 | 5 | 3 | 2 | 1 |
| Berlin UVI | 1 | 2 | 4 | 5 | 7 | 8 | 7 | 7 | 5 | 3 | 2 | 1 |
| Koeln UVI | 1 | 2 | 4 | 5 | 7 | 8 | 8 | 7 | 5 | 4 | 2 | 1 |
| Bonn | 1 | 2 | 4 | 5 | 7 | 8 | 8 | 7 | 5 | 4 | 2 | 1 |
| Frankfurt am Main UVI | 2 | 3 | 4 | 5 | 8 | 8 | 8 | 7 | 5 | 4 | 2 | 1 |
| Munich UVI | 2 | 3 | 5 | 6 | 8 | 9 | 9 | 8 | 6 | 4 | 2 | 1 |