Last updated: July 2, 2025
Understanding the UV Index is crucial for residents and visitors in Grenoble, France, where the picturesque Alpine backdrop can sometimes mask the intensity of sun exposure. With peak UV levels reaching as high as 10 during the summer months, being aware of UV levels plays a significant role in preventing sunburn and protecting skin health. As a city characterized by a Cfb climate, Grenoble offers a unique blend of sunshine and mountainous terrain, creating potential risks for those who enjoy outdoor activities. By staying informed about the UV Index, you can make smart choices to ensure a safe and enjoyable experience under the sun.
The UV Index rises steadily throughout the morning, starting low at 1 by 7:00 AM and 8 at noon. As the day progresses, it peaks at an impressive 10 between 2:00 PM and 3:00 PM, marking the highest exposure risk. After this peak, the index gently descends, with values dropping to 5 by 5:00 PM and settling at 2 by 7:00 PM. This data highlights the importance of sun safety during midday hours when the UV intensity is at its strongest, encouraging protective measures like sunscreen and shade.
| 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 | 7 | high | 25 min |
| 12:00 | 8 | very high | 15 min |
| 13:00 | 9 | 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 | 2 | low | 45 min |
Throughout the year, seasonal changes in UV exposure highlight significant fluctuations in the UV Index. The months of May through August are particularly high-risk, with UV Index values reaching a peak of 10, indicating very high exposure and a burn time of only 15 minutes. Visitors and residents should remain vigilant during these months, employing protective measures such as sunscreen and clothing, especially between 10 AM and 4 PM when UV exposure is strongest. March and April also show increased risk with UV Index values of 6 and 7 respectively. Conversely, January and December present lower risk levels, with UV Index values of 2 indicating low exposure and longer potential burn times of 45 minutes. It is essential to monitor UV levels year-round and adjust sun protection strategies accordingly to ensure safety.
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 |
| Grenoble | 2 | 4 | 6 | 7 | 9 | 10 | 10 | 9 | 7 | 5 | 3 | 2 |
| Toulouse UVI | 2 | 4 | 6 | 7 | 9 | 10 | 10 | 9 | 7 | 5 | 3 | 2 |