Last updated: August 1, 2025
In Ushibukamachi, Japan, understanding the UV Index is crucial for safeguarding your skin and overall health. With maximum UV levels peaking at an intense 13 around midday, awareness of these values helps prevent sunburn and long-term skin damage. The region's Cfa climate brings warm summers and plenty of sunshine, leading to increased UV exposure risks, particularly during the hours of 10 AM to 2 PM. By staying informed about the UV Index, residents and visitors can take proactive measures to enjoy the sun safely.
The UV Index exposure throughout the day exhibits a striking progression, peaking at 13 around noon. Starting from a gentle 1 at 7 AM, the index gradually escalates, hitting 3 by 8 AM. As the morning unfolds, it climbs to 5 by 9 AM, reaching a significant 9 by 10 AM. The afternoon sun intensifies, culminating in a maximum value of 11 at 11 AM before surging to its zenith at 12 PM. Following the high point, the index gradually declines, dropping to 12 at 1 PM, and tapering off to 10, 7, and finally 4 by mid to late afternoon. As the sun sets, the UV Index diminishes further, resting at 1 by 6 PM and continuing through 7 PM. It’s advisable to take precautions during peak hours, especially between 11 AM and 1 PM, to ensure safety under the sun.
| Time | UVI | Category | Time to Burn |
|---|---|---|---|
| 07:00 | 1 | low | 45 min |
| 08:00 | 3 | moderate | 30 min |
| 09:00 | 5 | moderate | 30 min |
| 10:00 | 8 | very high | 15 min |
| 11:00 | 10 | very high | 15 min |
| 12:00 | 12 | extreme | 10 min |
| 13:00 | 11 | extreme | 10 min |
| 14:00 | 10 | very high | 15 min |
| 15:00 | 7 | high | 25 min |
| 16:00 | 4 | moderate | 30 min |
| 17:00 | 2 | low | 45 min |
| 18:00 | 1 | low | 45 min |
| 19:00 | 1 | low | 45 min |
Throughout the year, UV radiation levels show significant seasonal variation, with high-risk months identified primarily from March to September. The UV Index reaches its peak in August at 13, indicating an extreme exposure category with a burn time of just 10 minutes. In contrast, during the winter months of December and January, the Index drops to moderate levels of 4 and 5, with longer burn times of 30 minutes. Visitors and residents are advised to take precautions during the high-risk months by wearing protective clothing, applying broad-spectrum sunscreen, and seeking shade to minimize sun exposure, especially during midday hours when UV radiation is strongest. As UV levels decrease in the fall and winter, awareness and protective measures can be relaxed somewhat, but some sun safety practices should still remain in place year-round.
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 |
| Osaka UVI | 4 | 6 | 8 | 11 | 11 | 11 | 12 | 11 | 10 | 7 | 5 | 3 |
| Ushibukamachi | 5 | 6 | 9 | 11 | 11 | 11 | 12 | 13 | 11 | 8 | 6 | 4 |