Last updated: May 3, 2025
Understanding the UV Index is crucial for residents of Bois-Guillaume, France, as it directly impacts your skin health and sunburn prevention. With a temperate maritime climate characterized by mild summers, the UV radiation can spike during peak hours, making awareness even more critical. On sunny days, UV levels can reach up to 8, indicating a high risk of harm from unprotected sun exposure between 12 PM and 2 PM. By keeping an eye on the UV Index, you can enjoy the beautiful outdoor settings of Bois-Guillaume while ensuring you take the necessary precautions to protect your skin from harmful effects.
As the sun rises, the UV Index gradually climbs, beginning at a mild 1 around 7:00 AM and 8:00 AM. By 9:00 AM, it nudges up to 2, creating a gentle warmth. The real action starts at 10:00 AM, when the index hits 3, and by midday, at 12:00 PM, it spikes to a steamy 7. The peak hours arrive between 1:00 PM and 2:00 PM with a maximum of 8, urging sun-seekers to take extra care. As the afternoon fades, the UV Index gradually recedes: 7 at 3:00 PM, 6 by 4:00 PM, and down to 2 by 7:00 PM. Ensure you’re protected during the peak, as the sun's influence intensifies before it begins to wane!
| 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 | 3 | moderate | 30 min |
| 11:00 | 5 | moderate | 30 min |
| 12:00 | 7 | high | 25 min |
| 13:00 | 7 | high | 25 min |
| 14:00 | 8 | very high | 15 min |
| 15:00 | 7 | high | 25 min |
| 16:00 | 6 | high | 25 min |
| 17:00 | 4 | 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 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Bois-Guillaume | 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 |