Last updated: July 2, 2025
In Vionnaz, Switzerland, staying informed about the UV Index is crucial for the health and safety of its residents and visitors. Understanding UV levels is essential not only for preventing painful sunburns but also for safeguarding your long-term skin health. With Vionnaz's high-altitude climate, the risk of UV exposure is significant, especially during peak hours when the index reaches 9, indicating a very high risk for harm from unprotected sun exposure. By staying updated on the UV Index, you can enjoy the beautiful Swiss outdoors while protecting yourself from potential damage.
As the day unfolds, the UV Index rises steadily, peaking around 1 PM when it reaches an impressive 9—the highest value of the day. Starting at a gentle 1 at 7 AM, the index remains low until 10 AM, when it climbs to 5. By 11 AM, it ramps up to 7 and continues to soar, hitting 8 at noon. The sun’s intensity is most formidable between 1 PM and 2 PM, inviting caution as outdoor plans peak. As afternoon transitions into evening, the index gradually recedes; by 6 PM, it drops to 3, concluding the day with a soft 1 at 7 PM. Stay protected during the peak hours to enjoy the outdoors safely!
| 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 | 7 | 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 | 7 | high | 25 min |
| 17:00 | 5 | moderate | 30 min |
| 18:00 | 3 | moderate | 30 min |
| 19:00 | 1 | low | 45 min |
Throughout the year, the UV Index exhibits significant seasonal variation, reflecting changes in sun exposure levels that can impact skin health. Low-risk months are observed in January, December, and to some extent, November with indexes of 2 to 3, allowing for longer burn times of 30 to 45 minutes. The risk then rises substantially starting in February, peaks during the summer months of May through August with very high ratings between 8 and 10—advising visitors and residents to minimize exposure to just 15 minutes during these months. March and April also present high UV levels, emphasizing the need for protective measures. As fall approaches in September and October, the UV Index decreases but remains moderate, suggesting continued caution. To stay safe, individuals should apply sunscreen, wear protective clothing, and seek shade especially during the high-risk months of May to August.
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 |
| 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 |
| Vionnaz | 2 | 4 | 6 | 7 | 8 | 10 | 9 | 9 | 7 | 5 | 3 | 2 |
| Lausanne UVI | 2 | 4 | 6 | 7 | 8 | 10 | 9 | 9 | 7 | 5 | 3 | 2 |