Last updated: July 2, 2025
In Biei, Japan, understanding the UV Index is crucial for maintaining skin health and preventing sunburn. With its unique Dfb climate, Biei experiences varying UV exposure throughout the day, peaking sharply from late morning to early afternoon. During these hours, the UV Index can reach a maximum of 10, indicating a high risk of harm from unprotected sun exposure. By staying informed about local UV levels, residents and visitors can take proactive measures to protect their skin, ensuring a safe and enjoyable time in the beautiful outdoors.
The UV Index today showcased a striking pattern, peaking with an intense maximum of 10 at 11:00 AM. As the sun climbed higher, levels steadily rose from 3 at 7:00 AM to a vibrant 8 by 10:00 AM, signaling the need for sun protection. After reaching its zenith, the index gradually declined, dropping to 9 at noon and tapering off throughout the afternoon—falling to 4 by 3:00 PM and dwindling to a mere 1 by 5:00 PM. This data serves as a reminder that while the sun's rays can be captivating, protecting your skin during peak hours is crucial for a safe and enjoyable outdoor experience!
| Time | UVI | Category | Time to Burn |
|---|---|---|---|
| 07:00 | 3 | moderate | 30 min |
| 08:00 | 5 | moderate | 30 min |
| 09:00 | 7 | high | 25 min |
| 10:00 | 8 | very high | 15 min |
| 11:00 | 10 | very high | 15 min |
| 12:00 | 9 | very high | 15 min |
| 13:00 | 8 | very high | 15 min |
| 14:00 | 7 | high | 25 min |
| 15:00 | 4 | moderate | 30 min |
| 16:00 | 3 | moderate | 30 min |
| 17:00 | 1 | low | 45 min |
| 18:00 | 1 | low | 45 min |
| 19:00 | 1 | low | 45 min |
Throughout the year, the UV Index experiences significant seasonal changes, impacting the risk of sunburn and the need for protective measures. The highest risk months are from May to September, characterized by very high UV Index levels of 9 to 10 and a burn time of just 15 minutes. In contrast, January and December present a much lower risk with a UV Index of 2, allowing for longer exposure times of 45 minutes. Residents and visitors are advised to take special care during peak months by wearing protective clothing, using sunscreen, and seeking shade to minimize UV exposure. As conditions fluctuate, it's essential to stay informed and adjust sun protection strategies accordingly.
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 |
| Biei | 2 | 3 | 6 | 7 | 9 | 9 | 10 | 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 |
| Osaka UVI | 4 | 6 | 8 | 11 | 11 | 11 | 12 | 11 | 10 | 7 | 5 | 3 |