Last updated: May 3, 2025
Awareness of the UV Index is crucial for residents and visitors in Himeji, Japan, where the climate falls under the Cfa classification, characterized by hot summers and mild winters. Understanding UV levels allows individuals to take essential precautions against harmful sun exposure, helping to prevent sunburn and promote long-term skin health. With peak UV levels reaching as high as 11 around midday, it’s vital to stay informed about the risks of overexposure—especially when considering the sunny days that are typical for Himeji. Protect your skin and enjoy the beautiful outdoors by keeping an eye on the UV Index!
The UV Index for the day follows a dynamic trend, peaking during the midday hours. Starting at a modest 2 at 7:00 AM, the intensity gradually intensifies, reaching 4 by 8:00 AM. As the sun climbs higher, the index escalates significantly, hitting a striking 9 at 10:00 AM and reaching its zenith of 11 at 12:00 PM. After this peak, a gradual decline sets in, with the index dropping to 5 by 3:00 PM before tapering off to 1 by 5:00 PM. The day concludes with a UV Index of 0 by 7:00 PM, signaling a clear drop in potential UV exposure. It's a reminder to stay sun-smart, especially during the midday hours when the UV rays are at their strongest!
| Time | UVI | Category | Time to Burn |
|---|---|---|---|
| 07:00 | 2 | low | 45 min |
| 08:00 | 4 | moderate | 30 min |
| 09:00 | 6 | high | 25 min |
| 10:00 | 9 | very high | 15 min |
| 11:00 | 10 | very high | 15 min |
| 12:00 | 11 | extreme | 10 min |
| 13:00 | 10 | very high | 15 min |
| 14:00 | 8 | very high | 15 min |
| 15:00 | 5 | moderate | 30 min |
| 16:00 | 3 | moderate | 30 min |
| 17:00 | 1 | low | 45 min |
| 18:00 | 1 | low | 45 min |
| 19:00 | 0 | low | 45 min |
Throughout the year, UV exposure fluctuates significantly, with high-risk months occurring from March to September. The UV Index peaks in July at 12, categorized as extreme, with only 10 minutes until burn time. Both April and May also present critical UV levels of 11. Residents and visitors should exercise caution during these months, wearing protective clothing, using sunscreen of SPF 30 or higher, and seeking shade during peak sunlight hours. In contrast, January, November, and December offer a more moderate UV Index of 4 to 5, with burn times of 30 minutes or more, making sun protection less critical during this period. Continuous awareness of seasonal UV changes is essential for health and safety.
UV Risk Categories
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sapporo UVI | 2 | 3 | 6 | 7 | 9 | 9 | 9 | 10 | 8 | 5 | 3 | 2 |
| Yokohama UVI | 3 | 5 | 8 | 9 | 11 | 11 | 11 | 11 | 10 | 7 | 5 | 4 |
| Tokyo UVI | 3 | 5 | 8 | 9 | 11 | 11 | 11 | 11 | 10 | 7 | 5 | 4 |
| Nagoya UVI | 4 | 6 | 8 | 10 | 11 | 11 | 11 | 11 | 10 | 7 | 5 | 3 |
| Himeji | 4 | 6 | 8 | 11 | 11 | 11 | 12 | 11 | 10 | 7 | 5 | 4 |
| Osaka UVI | 4 | 6 | 8 | 11 | 11 | 11 | 12 | 11 | 10 | 7 | 5 | 3 |