Last updated: July 2, 2025
In Crolles, France, being aware of the UV Index is crucial for safeguarding your skin against damaging sun exposure. Understanding UV levels helps you take precautionary measures to prevent sunburn and maintain skin health, particularly during the summer months when the sun's rays are most intense. With a Cfb climate that features mild summers and varying UV exposure throughout the day, Crolles residents and visitors must be vigilant, especially as UV Index levels can peak as high as 10 around midday. Stay informed and protect yourself from the sun’s harmful effects!
As the sun rises, the UV Index starts off low, hitting just 1 by 07:00 and maintaining that level through 08:00. However, as the morning progresses, anticipation builds with a steady climb to 3 by 09:00 and peaking at a noteworthy 5 by 10:00. The intensity escalates sharply, reaching a maximum of 10 between 13:00 and 14:00, indicating a significant risk for unprotected skin. Gradually, the UV Index begins to decline, dropping back to 9 at 15:00 and easing down to 5, 3, and finally 2 as the day winds down through 17:00 to 19:00. A day to remember for sun seekers, but remember to apply that sunscreen during peak hours!
| 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 | 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 | 2 | low | 45 min |
Throughout the year, the UV Index demonstrates significant seasonal changes, with the highest levels occurring during the summer months. From March to August, the UV Index reaches high to very high categories, peaking at 10 in June and July, when the burn time is as little as 15 minutes. The high-risk months for sun exposure are April through August, where individuals should take precautionary measures. Residents and visitors are advised to use sunscreen, wear protective clothing, and seek shade to minimize the risk of skin damage during these months. As the year progresses into fall and winter, the UV Index decreases, reaching a low of 2 in December, where a burn time of 45 minutes is typical; however, caution should still be exercised when outdoors.
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 |
| Crolles | 3 | 4 | 6 | 8 | 9 | 10 | 10 | 9 | 7 | 5 | 3 | 2 |