Last updated: June 2, 2025
Understanding the UV Index is crucial for residents and visitors of Rosny-sur-Seine, France, where the climate fosters significant sun exposure, especially during peak hours. As UV levels rise, so does the risk of sunburn and long-term skin damage, making it essential to stay informed. With a typical Cfb climate characterized by warm summers, the UV Index can peak at a high level of 9 around midday, underscoring the importance of sun safety practices. Being aware of these UV levels empowers you to protect your skin and enjoy the beautiful, sunlit days that Rosny-sur-Seine has to offer.
The UV Index today reveals a dramatic rise in sun exposure as the day progresses. Starting gently at 1 during the early hours, by 10:00 AM it peaks to 4, signaling an increase in sun intensity. The UV levels continue to ascend, reaching their maximum at 1:00 PM and 2:00 PM, where they hit an impressive 9. As the afternoon rolls on, the values begin to taper off to 8 by 3:00 PM and gradually decline through the evening, settling at 2 by 7:00 PM. It's a brilliant reminder to stay protected from the sun, especially during peak hours!
| 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 | 6 | high | 25 min |
| 12:00 | 7 | high | 25 min |
| 13:00 | 9 | very high | 15 min |
| 14:00 | 9 | 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 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Rosny-sur-Seine | 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 |