Last updated: August 1, 2025
Understanding the UV Index is crucial for residents of Yabuki, Japan, as it provides essential insights into daily sun exposure risks and helps protect against harmful effects like sunburn and long-term skin health issues. With a humid subtropical climate (Cfa), Yabuki experiences intense UV radiation, particularly during the midday hours when values soar to levels of 11. By staying informed about the UV levels throughout the day, you can take proactive steps to enjoy the sun safely and prioritize your skin's health while minimizing risks associated with excessive exposure.
As the day unfolds, the UV Index begins to climb, starting at a mild 2 by 07:00. By 08:00, it ascends to a moderate 5, indicating that sun protection becomes essential. The intensity peaks at 11 between 11:00 and 12:00, marking the hours when solar radiation is most potent. Following this peak, the index gradually declines; it drops to 10 at 13:00, before descending to 7 by 14:00. The afternoon sees a further decrease, with readings of 5 at 15:00 and 3 at 16:00—perfect for those wishing to enjoy the sun while still being cautious. By 17:00, the index falls to a mild 1, and as the day winds down, it reaches 0 by 19:00, signaling a retreat from the sun's harmful rays. It’s crucial to stay informed and protect your skin during peak UV hours!
| Time | UVI | Category | Time to Burn |
|---|---|---|---|
| 07:00 | 2 | low | 45 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 |
The seasonal UV variations indicate a significant increase in UV exposure from winter to summer, with high-risk months emerging from April through August. During this period, the UV Index peaks at 11 (extreme), particularly in June, July, and August, where the burn time drops to just 10 minutes. Visitors and residents are advised to take precautionary measures during these months, such as seeking shade, wearing protective clothing, and applying sunscreen frequently. As the UV levels decrease in the fall and winter months, with indices dropping to 3 in January and December, the risk of sunburn diminishes. However, maintaining sun safety practices year-round remains essential for health and well-being.
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 |
| Yabuki | 3 | 5 | 7 | 9 | 10 | 11 | 11 | 11 | 9 | 7 | 5 | 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 |