Last updated: June 2, 2025
In Yuzawa, Japan, understanding the UV Index is crucial for protecting your skin and overall health. With UV levels peaking at 10 during midday hours, awareness is key to preventing sunburn and long-term skin damage. The region's humid continental climate brings a mix of seasonal weather, but during sunnier months, the UV exposure can be significant. By staying informed about daily UV levels, residents and visitors can better enjoy outdoor activities while safeguarding their skin against harmful UV rays.
During the day, the UV Index experiences a dynamic shift, peaking in the late morning. Starting at 3 at 07:00, it escalates to reach a high of 10 by 11:00 and remains there until 12:00. As afternoon approaches, the index gradually declines, dropping back to 9 by 13:00, then to 7 at 14:00. By the mid to late afternoon, it continues its descent, falling to 5 at 15:00 and further down to 3 by 16:00. In the evening, the index diminishes significantly, plummeting to 1 at both 17:00 and 18:00, and finally reaching 0 by 19:00. This pattern highlights the importance of sun protection during the peak hours of 10:00 to 12:00 when the UV radiation is most intense.
| 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 | 9 | very high | 15 min |
| 11:00 | 10 | very high | 15 min |
| 12:00 | 10 | very high | 15 min |
| 13:00 | 9 | 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 notable fluctuations, with high-risk months occurring between April and August. In April and May, the UV index peaks at 9, categorized as very high, requiring quick precautions with just 15 minutes of burn time. June and July sustain a UV Index of 10, also indicating very high levels, while August reaches an extreme UV Index of 11, minimizing safe sun exposure to just 10 minutes. In contrast, the UV levels are moderate from January to February and again from October to December, notably lowering burn times back to 30 minutes. Visitors and residents are strongly advised to protect their skin with sunscreen, hats, and protective clothing especially during the highest UV Index periods, ensuring they avoid prolonged sun exposure during peak hours. Stay informed and prioritize skin safety!
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 |
| Yuzawa | 3 | 4 | 6 | 9 | 9 | 10 | 10 | 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 |