Last updated: July 2, 2025
Understanding the UV Index is crucial for residents and visitors in Bonn, Germany, where the climate fosters both outdoor enjoyment and UV exposure risks. With the UV Index peaking at levels 7 to 8 during midday hours, it's essential to be aware of these fluctuations to protect your skin health and prevent painful sunburns. Bonn's temperate maritime climate means that while the sun’s intensity may vary with the seasons, the potential for UV-related skin damage remains a concern year-round. Staying informed about UV levels can help ensure a safe and enjoyable experience under the Bonn sun!
As the sun rises, the UV Index begins at a mild 1 during the early hours (07:00 and 08:00), making it a safe start for morning activities. However, the intensity ramps up quickly, peaking at 8 between 13:00 and 14:00—a critical time where sun protection is essential. From 10:00 onward, the index steadily climbs to reach its midday high of 7 at 12:00, signaling the strongest UV exposure. As the day progresses, levels gradually decrease, dipping to 4 by 17:00 and returning to a safer 1 by 19:00. Stay vigilant during the peak hours for your skin’s safety!
| 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 | 4 | moderate | 30 min |
| 11:00 | 6 | high | 25 min |
| 12:00 | 7 | high | 25 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 |