Last updated: June 2, 2025
In Konan, Japan, being aware of the UV Index is crucial for safeguarding your skin and overall health. Understanding UV levels is key to preventing sunburn and reducing long-term skin damage, especially in a region that experiences a humid subtropical climate (Cfa), where UV exposure can vary dramatically throughout the day. With peak UV Index values reaching as high as 11 around midday, residents and visitors alike must stay informed to enjoy outdoor activities safely. Whether you're basking in the sun or engaging in outdoor sports, knowing the UV Index can help you take the necessary precautions to protect your skin from harmful rays.
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 exposure varies significantly, peaking during the summer months. High-risk months for UV exposure are from March to August, when the UV Index reaches its maximum levels of 10 to 11 and the burn time is as brief as 10 minutes. Notably, May through August features extreme exposure, requiring diligent sun protection practices. As the year transitions into fall, September to November sees a decrease in UV levels, with October still posing a moderate risk. To ensure safety, visitors and residents are advised to wear protective clothing, use sunscreen, and seek shade during the peak sun hours, especially from late spring through summer when the threat of sunburn is greatest.
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 |
| Konan | 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 |