Last updated: July 2, 2025
In Mortefontaine-en-Thelle, France, being aware of the UV Index is essential for safeguarding your skin and health against the sun's potentially harmful rays. Understanding UV levels helps in preventing sunburn and reducing the long-term risk of skin damage, making it crucial for everyone to monitor these daily readings. Nestled in a Cfb climate zone, Mortefontaine-en-Thelle experiences significant UV exposure, especially during the midday hours when UV Index values can peak at 8. This makes it important to take precautions, such as seeking shade and applying sunscreen, to enjoy the sun safely while protecting your skin's health.
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, the UV Index experiences significant fluctuations, with high-risk months identified primarily from April to August, where the index peaks at an alarming 9 in June. During these months, the exposure category escalates to very high, resulting in a burn time of just 15 minutes for unprotected skin. In contrast, January, November, and December have low UV levels, making sun protection less critical, with burn times extending to 45 minutes. As such, it’s essential for both visitors and residents to stay vigilant during the peak months by applying broad-spectrum sunscreen, wearing protective clothing, and seeking shade, especially between 10 AM and 4 PM, when UV rays are strongest.
UV Risk Categories
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Mortefontaine-en-Thelle | 2 | 3 | 4 | 6 | 8 | 9 | 8 | 8 | 6 | 4 | 2 | 1 |
| 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 |