Last updated: July 2, 2025
In Hokuryu, Japan, staying informed about the UV Index is crucial for safeguarding your skin and overall health. Understanding UV levels can significantly aid in sunburn prevention and maintaining long-term skin wellness, especially as exposure can lead to serious health issues over time. With Hokuryu’s Dfb climate, residents often face varying UV exposure risks, particularly during peak hours when indices soar to 9—a level that calls for immediate sun protection strategies. By following UV Index updates, you can enjoy the beautiful outdoors while keeping your skin safe from harmful rays.
At 07:00, the UV Index begins at a modest 3, signaling a gentle start to the day. By 08:00, it climbs to 5, suggesting it's time to apply some sunscreen if you plan to be outdoors. As the sun reaches its peak around 10:00, the index hits a robust 8 and reaches its pinnacle at 11:00 and 12:00 with a peak of 9. This signifies a high risk of harm from unprotected sun exposure, making it crucial to seek shade or wear protective clothing during these hours. As the afternoon progresses, the index gradually decreases, dropping to 7 by 14:00, then to 4 at 15:00, and finally tapering off to 3 by 16:00. As the day winds down, the UV Index diminishes further, falling to 1 from 17:00 onward, indicating minimal risk for sun exposure. Stay safe and be sun smart!
| 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 | 9 | 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 |
The UV Index shows a clear seasonal variation, with high-risk months from March to September, where values peak at 10 in August. January and December experience low exposure with a UV Index of 2, while February and November have moderate exposure with an index of 3. During April and May, the UV Index rises significantly, reaching very high levels of 8 and 9, meaning a burn time of just 15 minutes is recommended during peak intensity months. Visitors and residents should take precautions from March through September, especially midday, to protect their skin, including wearing sunscreen, protective clothing, and seeking shade. As UV levels drop in the fall and winter, there is less risk, but some protection is still advisable in February and October.
UV Risk Categories
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Hokuryu | 2 | 3 | 6 | 7 | 8 | 9 | 9 | 10 | 8 | 5 | 3 | 2 |
| 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 |
| Osaka UVI | 4 | 6 | 8 | 11 | 11 | 11 | 12 | 11 | 10 | 7 | 5 | 3 |