Last updated: July 2, 2025
Understanding the UV Index in Willisau, Switzerland, is crucial for protecting your skin and overall health. With the region's Cfb climate, residents and visitors alike are exposed to varying UV levels throughout the day, peaking at an index of 9 from 1 PM to 2 PM. This means the risk of sunburn and long-term skin damage can rise significantly during these hours. By staying informed about the UV Index, you can take essential precautions to enjoy the sun while keeping your skin safe from harmful UV radiation. Be aware and stay protected!
A beautiful day unfolds as the UV Index climbs steadily throughout the morning and peaks during the afternoon. Starting at a gentle 1 at 07:00, it gradually rises to a moderate 3 by 09:00. The intensity increases further, reaching a noticeable 5 at 10:00 and hitting a striking 6 at 11:00. Just after midday, the UV Index reaches its zenith at 9 between 13:00 and 14:00, signaling the importance of protective measures. As the sun starts to descend, values ease back to 8 at 15:00, before gradually dropping to 4 at 17:00 and returning to a safe 1 by 19:00. This progression emphasizes the need for awareness and protection from UV rays, especially during the midday heat.
| 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 | 5 | moderate | 30 min |
| 11:00 | 6 | high | 25 min |
| 12:00 | 8 | very high | 15 min |
| 13:00 | 9 | very high | 15 min |
| 14:00 | 9 | very high | 15 min |
| 15:00 | 8 | very high | 15 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 exposure fluctuates significantly, with the highest risk months occurring from May to August, when the UV Index reaches levels categorized as very high (UV Index 8-9). During these months, the burn time drastically decreases to just 15 minutes, emphasizing the need for protection. Conversely, the low risk months of January, November, and December offer a safer environment with a UV Index of 2 and a burn time of 45 minutes. As such, visitors and residents should be particularly vigilant during peak summer months by wearing sunscreen, protective clothing, and seeking shade during peak sun hours, while enjoying the milder winter months with less concern for UV exposure.
UV Risk Categories
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Basel UVI | 2 | 3 | 5 | 6 | 8 | 9 | 9 | 8 | 6 | 4 | 2 | 1 |
| Willisau | 2 | 3 | 5 | 6 | 8 | 9 | 9 | 8 | 6 | 4 | 2 | 2 |
| Bern UVI | 2 | 3 | 5 | 6 | 8 | 9 | 9 | 8 | 6 | 4 | 2 | 2 |
| Zurich UVI | 2 | 3 | 5 | 6 | 8 | 9 | 9 | 8 | 6 | 4 | 3 | 2 |
| Geneve UVI | 2 | 3 | 6 | 7 | 8 | 10 | 9 | 8 | 7 | 5 | 3 | 2 |
| Lausanne UVI | 2 | 4 | 6 | 7 | 8 | 10 | 9 | 9 | 7 | 5 | 3 | 2 |