Last updated: July 2, 2025
Understanding the UV Index is crucial for residents and visitors of Thoiry, France, where sun exposure can vary significantly throughout the day. With a climate marked by mild summers, it's essential to recognize the levels of UV radiation, especially during peak hours between 11:00 AM and 3:00 PM, when values soar to a maximum of 9. Monitoring these levels not only helps prevent painful sunburns but also contributes to long-term skin health. As Thoiry's UV exposure can lead to increased risks during warmer months, staying informed can make all the difference in enjoying the sun safely.
The UV Index data reveals a significant increase in solar exposure throughout the day. Starting with a low of 1 at 07:00, the index gradually rises to 3 by 09:00. The sun reaches its peak intensity at 13:00 and 14:00 with a striking 9, indicating a high risk of harm from unprotected sun exposure. As the afternoon progresses, the index slightly declines but remains notable at 8 until 15:00, before tapering off towards the evening. By 19:00, the UV Index drops back to 1, marking a safe return for outdoor activities as the sun sets. For those planning outdoor adventures, it’s essential to stay protected during the 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 | 4 | moderate | 30 min |
| 11:00 | 6 | high | 25 min |
| 12:00 | 8 | very high | 15 min |
| 13:00 | 9 | very high | 15 min |
| 14:00 | 9 | very high | 15 min |
| 15:00 | 8 | 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 |
The UV Index experiences significant seasonal variation, with the highest levels occurring from March to August. During this period, the high-risk months are typically April through August, where the UV Index reaches its peak values of 8 to 10, indicating a very high exposure category and a quick burn time of just 15 minutes. In contrast, the winter months of January and December present lower UV Index values (2), categorized as low exposure, allowing for a longer burn time of up to 45 minutes. It is essential for both visitors and residents to take precautions during high UV Index months, such as wearing sunscreen, protective clothing, and seeking shade, especially between 11 a.m. and 4 p.m. when the sun’s rays are 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 |
| Lyon UVI | 2 | 3 | 5 | 6 | 8 | 10 | 9 | 8 | 6 | 5 | 3 | 2 |
| Thoiry | 2 | 3 | 6 | 7 | 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 |