Last updated: June 2, 2025
In Tosa, Japan, staying informed about the UV Index is crucial for safeguarding your skin health and preventing uncomfortable sunburns. With a humid subtropical climate (Cfa), Tosa experiences significant UV exposure, especially during peak hours from 10 AM to 1 PM, when levels can soar to 12—the highest on the scale. Understanding UV levels not only helps you enjoy the beautiful Tosa outdoors safely but also plays a vital role in long-term skin protection. Whether you're soaking in the sun or enjoying an outdoor adventure, being UV-aware can make all the difference in your daily routine.
As the day unfolds, the UV Index climbs steadily, peaking at a striking 12 around noon, signaling a high risk for skin damage without protection. Early risers at 07:00 encounter a mild 2, but the intensity increases quickly, reaching 9 by 10:00 and a critical 11 by 11:00. From 12:00 to 13:00, the index holds its highest point at 12, making it essential to seek shade or apply sunscreen. After 13:00, the UV levels gradually decrease, dropping back to a manageable 4 by 16:00 and winding down to a safe 1 by 18:00. This hourly data serves as a reminder to take sun safety precautions, especially during 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 | 12 | extreme | 10 min |
| 13:00 | 11 | extreme | 10 min |
| 14:00 | 9 | very high | 15 min |
| 15:00 | 6 | 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, the UV Index experiences significant fluctuations, with the highest risk months occurring from March to August, where it often reaches extreme levels. Notably, April, May, June, July, and August all register a UV Index of 12, indicating critical exposure levels with a burn time of only 10 minutes. Visitors and residents should take precautions during these months, such as wearing sunscreen, protective clothing, and seeking shade during peak sun hours. Conversely, from January to February and October to November, the UV levels are lower, categorized as moderate to high, allowing for a more comfortable outdoor experience, although caution is still advised. In December, the UV Index drops back to 4, reverting to a moderate category where burn time extends to 30 minutes, making it the safest month for outdoor activities. Overall, awareness of the UV Index can help individuals protect themselves from harmful sun exposure 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 |
| Tosa | 4 | 6 | 9 | 11 | 11 | 12 | 12 | 12 | 10 | 7 | 6 | 4 |