Last updated: July 2, 2025
Understanding the UV Index is crucial for residents and visitors in Kaminoyama, Japan. With varying levels of ultraviolet radiation throughout the day, being aware of these levels helps prevent sunburn and protects overall skin health. In this region, characterized by a Dfa climate, you can expect high UV exposure, especially during the peak hours of 11:00 AM to 1:00 PM when the UV Index reaches as high as 11. Knowledge of UV levels empowers you to enjoy the beautiful outdoors while safeguarding your skin from potential harm.
During the day, the UV Index experiences a significant peak, reaching a maximum of 11 between 11:00 AM and 12:00 PM, indicating a very high risk of harm from unprotected sun exposure. The index rises steadily from 3 at 7:00 AM to hit 9 at 10:00 AM, before surging past 10 just before noon. As the afternoon progresses, the intensity of UV rays begins to decline, dropping to 7 by 2:00 PM and further down to 5 by 3:00 PM. Transitioning into the evening, the threat diminishes significantly, with the UV Index plummeting to 1 by 5:00 PM and eventually reaching 0 after 7:00 PM. It's essential to take precautions during the peak hours to protect your skin from harmful UV radiation!
| Time | UVI | Category | Time to Burn |
|---|---|---|---|
| 07:00 | 3 | moderate | 30 min |
| 08:00 | 4 | moderate | 30 min |
| 09:00 | 7 | high | 25 min |
| 10:00 | 9 | 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 | 7 | high | 25 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, the UV Index experiences significant fluctuations, peaking during the summer months. January and December see a moderate UV Index of 3, with a burn time of 30 minutes. As early as February, the Index rises to 5, indicating a continued moderate exposure. However, March marks the onset of high risk with an Index of 7, reducing burn time to 25 minutes. The real concern arises from April to August, where the Index reaches very high (9-10) and even extreme levels (11) in July and August, with dangerously short burn times of just 10-15 minutes. The season begins to taper off in September (UV Index 9) and October (UV Index 6), before returning to moderate levels in November and December. For visitors and residents, it is crucial to take protective measures, especially from April to August, by seeking shade, wearing protective clothing, and applying sunscreen rigorously to prevent harmful UV exposure.
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 |
| Kaminoyama | 3 | 5 | 7 | 9 | 10 | 10 | 11 | 11 | 9 | 6 | 4 | 3 |
| 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 |