Last updated: June 2, 2025
Understanding the UV Index in Yuasa, Japan is crucial for safeguarding your skin health and preventing sunburn during the warm months. With the local climate characterized as Cfa, which features hot, humid summers, residents and visitors alike face varying levels of UV exposure throughout the day. On particularly sunny days, the UV Index can soar to as high as 11, highlighting the importance of being aware of UV levels to make informed decisions about sun protection. By knowing when to seek shade or apply sunscreen, you can enjoy the beautiful days in Yuasa while keeping your skin safe from harmful UV radiation.
As the sun rises, the UV Index begins its ascent, starting at a gentle 2 at 07:00. By 08:00, it climbs to 4, indicating that protective measures are beginning to be advisable. The intensity peaks at 11 during the 11:00 and 12:00 hours, marking the time when sunlight is most potent. As the afternoon progresses, the index starts to decline; by 14:00, it drops to 8, and further diminishes to 6 by 15:00. As evening approaches, the UV Index wanes significantly, reducing to 3 at 16:00 and sinking to a mild 1 by 18:00, indicating a much lower risk. Overall, it’s a sun-soaked day, urging outdoor enthusiasts to be mindful of sun exposure, especially during those peak hours!
| Time | UVI | Category | Time to Burn |
|---|---|---|---|
| 07:00 | 2 | low | 45 min |
| 08:00 | 4 | moderate | 30 min |
| 09:00 | 6 | 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 | 8 | very high | 15 min |
| 15:00 | 6 | high | 25 min |
| 16:00 | 3 | 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 index values show significant seasonal changes, with the highest risk months occurring from April to August, when the UV index reaches extreme levels of 11 to 12. This period, particularly in July, presents the shortest burn time of just 10 minutes, indicating the need for serious sun protection. As spring approaches in March, the index rises to a very high level of 8, making it essential for residents and visitors to start incorporating sun safety measures early. As we transition into the fall and winter months, the UV index drops, with February and October still posing moderate to high risk, while January and December return to a more moderate level. To ensure safety during peak UV times, it's crucial to apply sunscreen liberally, wear protective clothing, and seek shade whenever spending extended periods outdoors.
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 |
| Yuasa | 4 | 6 | 8 | 11 | 11 | 11 | 12 | 11 | 10 | 7 | 6 | 4 |