Last updated: June 2, 2025
Understanding the UV Index in Chamonix-Mont-Blanc is crucial for enjoying the stunning alpine scenery while protecting your skin. High elevation and expansive outdoor activities in this breathtaking region mean UV exposure levels can reach significant heights, particularly between 10 AM and 3 PM when the index peaks at 10. By staying informed about UV levels, you can prevent sunburn and promote overall skin health, ensuring that your adventures in the Dfc climate of Chamonix are safe and enjoyable. So before you hit the slopes or hike the trails, check the UV Index to stay one step ahead of sun-related risks.
The UV Index demonstrates a notable progression throughout the day, starting at a mild 1 at 07:00 and rapidly climbing to reach its peak of 10 between 13:00 and 14:00. As the sun reaches its zenith, the radiation intensifies, signaling the need for sun protection. From 11:00, the index rises sharply, hitting 8 at 11:00 and peaking at 9 by 12:00. As the afternoon rolls in, values maintain a high level before gradually declining, dropping to 7 at 16:00 and falling to 1 again by 19:00. This dynamic fluctuation emphasizes the importance of safeguarding your skin during the hours of peak sun exposure!
| 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 | 8 | very high | 15 min |
| 12:00 | 9 | very high | 15 min |
| 13:00 | 10 | very high | 15 min |
| 14:00 | 10 | very high | 15 min |
| 15:00 | 9 | 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 |
As the seasons change, so does the UV Index, reflecting varying levels of sun exposure risk. From January to February, the UV Index remains relatively moderate, with a value of 3-4 and a burn time of 30 minutes. However, starting in March, the UV Index rises significantly, reaching high levels of 7 and subsequently peaking at 10 in June and July, marking the months of highest risk. April to August features very high UV Index ratings (8-10), with a critical burn time of only 15 minutes, making it essential for visitors and residents to take precautionary measures by wearing sunscreen, hats, and protective clothing during these months. With a decline in UV exposure in September (7) and further into the fall and winter months, the UV Index drops to moderate (5) in October and then to low (2) by December, allowing for safer outdoor activities. Overall, it is crucial to be vigilant, especially during the high-risk months of March through August, to ensure skin protection against harmful UV radiation.
UV Risk Categories
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Paris UVI | 2 | 3 | 5 | 6 | 8 | 9 | 8 | 8 | 6 | 4 | 2 | 1 |
| Lyon UVI | 2 | 3 | 5 | 6 | 8 | 10 | 9 | 8 | 6 | 5 | 3 | 2 |
| Nice UVI | 2 | 4 | 6 | 7 | 8 | 10 | 9 | 8 | 7 | 5 | 3 | 2 |
| Marseille UVI | 2 | 4 | 5 | 7 | 9 | 10 | 9 | 8 | 7 | 5 | 3 | 2 |
| Toulouse UVI | 2 | 4 | 6 | 7 | 9 | 10 | 10 | 9 | 7 | 5 | 3 | 2 |
| Chamonix-Mont-Blanc | 3 | 4 | 7 | 8 | 9 | 10 | 10 | 9 | 7 | 5 | 3 | 2 |