Last updated: June 2, 2025
Understanding the UV Index is essential for residents and visitors in Tamamura, Japan, where the subtropical Cfa climate brings sunny days and high UV exposure risks. With peak index values reaching 11—indicating extremely high levels of UV radiation—being informed about these fluctuations is crucial for effective sunburn prevention and maintaining long-term skin health. By staying aware of daily UV levels, you can enjoy outdoor activities while minimizing potential harm from the sun and protecting your skin from premature aging and other UV-related issues.
As the sun rises, the UV Index begins to climb, starting at a mild 3 at 07:00. By 08:00, it reaches a moderate 5, signaling that it's time to start thinking about sun protection. The intensity peaks at 11 from 11:00 to 12:00, marking the highest risk period of the day. As the afternoon progresses, the UV Index gradually declines, dropping to 8 at 14:00 before dwindling to 5 by 15:00. As the day winds down, the index continues to fall, hitting a low of 1 from 16:00 to 18:00, and finally reaching 0 after 19:00. It’s essential to stay vigilant and take precautions during the peak hours to enjoy the sunshine safely!
| 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 | 10 | very high | 15 min |
| 11:00 | 11 | extreme | 10 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 varies significantly, with the highest risk months being May through August when the UV Index reaches an extreme level of 11. During these months, the recommended burn time is reduced to just 10 minutes, necessitating vigilant sun protection practices. Notably, March and April also present high risk, characterized by very high UV indices of 8 and 9, respectively, with burn times of just 15 minutes. As UV levels taper off from September to December, residents and visitors should remain cautious, especially in the early months of spring. It’s vital for everyone to stay informed about UV levels and take appropriate protective measures, such as applying sunscreen, wearing protective clothing, and seeking shade, particularly during peak hours.
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 |
| Tamamura | 4 | 6 | 8 | 9 | 11 | 11 | 11 | 11 | 10 | 7 | 5 | 3 |
| 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 |