Last updated: June 2, 2025
Understanding the UV Index is essential for residents and visitors of Unterwasser, Switzerland, where stunning Alpine landscapes come with a side of sun exposure. As a region characterized by a Cfb climate, the UV levels can fluctuate significantly throughout the day, peaking at a notably high level of 10 around midday. Being aware of UV levels is crucial for sunburn prevention and maintaining long-term skin health, especially when engaging in outdoor activities. With intense afternoon sunlight posing a greater risk, staying informed enables you to enjoy the beautiful surroundings while safeguarding your skin against harmful UV rays.
As the sun rises, the UV Index gradually climbs, beginning at a mild 1 at 7:00 AM. By 9:00 AM, it reaches 3, prompting early risers to consider sun protection. The intensity peaks at 1:00 PM with a maximum of 10, signaling the most hazardous conditions for unprotected skin. As the afternoon unfolds, the index dips from 9 at 2:00 PM to 6 by 4:00 PM, offering a brief respite. As the day winds down, the UV rays decrease, falling to 2 by 6:00 PM and returning to a safe 1 by 7:00 PM. Stay mindful of these fluctuations to enjoy the sun while safeguarding your skin!
| 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 | 7 | high | 25 min |
| 12:00 | 9 | very high | 15 min |
| 13:00 | 10 | 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 | 2 | low | 45 min |
| 19:00 | 1 | low | 45 min |
The UV Index experiences significant seasonal variation, with the highest levels occurring from March to August. During this period, the high-risk months are typically April through August, where the UV Index reaches its peak values of 8 to 10, indicating a very high exposure category and a quick burn time of just 15 minutes. In contrast, the winter months of January and December present lower UV Index values (2), categorized as low exposure, allowing for a longer burn time of up to 45 minutes. It is essential for both visitors and residents to take precautions during high UV Index months, such as wearing sunscreen, protective clothing, and seeking shade, especially between 11 a.m. and 4 p.m. when the sun’s rays are strongest.
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 |
| Unterwasser | 2 | 3 | 6 | 7 | 8 | 10 | 9 | 8 | 6 | 5 | 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 |