Last updated: July 2, 2025
In Boullay-les-Troux, France, understanding the UV Index is crucial for protecting your skin and overall health. With peak UV levels reaching as high as 8 during midday, awareness of these readings can significantly reduce your risk of sunburn and long-term skin damage. The Cfb climate of this picturesque locale brings a blend of temperate weather and varying sun exposure, making it essential to stay informed about daily UV radiation levels. By knowing when to seek shade or apply sunscreen, you can enjoy the beautiful French countryside while safeguarding your skin from harmful UV rays.
As the day begins, the UV Index stays low, peaking at 1 during the early hours from 07:00 to 08:00. However, as the sun rises higher, the intensity of ultraviolet radiation climbs sharply. By 10:00, it reaches 4, and by midday, it escalates to an impressive 7. The afternoon is marked by the highest levels between 13:00 and 15:00, where the UV Index soars to 8—a potent reminder of the sun's power. As the sun begins to dip, the UV levels gradually decline, settling at 5 by 17:00 and tapering off to 2 by 19:00. This hourly data highlights the importance of sun protection during peak hours, especially from 11:00 to 15:00, when UV exposure is at its highest.
| Time | UVI | Category | Time to Burn |
|---|---|---|---|
| 07:00 | 1 | low | 45 min |
| 08:00 | 1 | low | 45 min |
| 09:00 | 2 | low | 45 min |
| 10:00 | 4 | moderate | 30 min |
| 11:00 | 5 | moderate | 30 min |
| 12:00 | 7 | high | 25 min |
| 13:00 | 8 | very high | 15 min |
| 14:00 | 8 | very high | 15 min |
| 15:00 | 8 | very high | 15 min |
| 16:00 | 6 | high | 25 min |
| 17:00 | 5 | moderate | 30 min |
| 18:00 | 3 | moderate | 30 min |
| 19:00 | 2 | low | 45 min |
Throughout the year, UV levels vary significantly, with the highest risk months occurring from May to August, where the UV Index reaches a peak of 9 in June and remains at 8 during July and August, indicating a very high exposure category and a critical burn time of just 15 minutes. In contrast, winter months see much lower UV levels, with January and November registering a UV Index of 2 and December dropping to 1, categorized as low exposure. Visitors and residents should exercise caution during the high-risk months by minimizing sun exposure, wearing protective clothing, and applying sunscreen regularly, particularly between late spring and early fall when UV radiation is at its strongest.
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 |
| Boullay-les-Troux | 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 |