Last updated: August 1, 2025
Understanding the UV Index is crucial for residents and visitors of Tosa, Japan, where the Cfa climate brings warm summers and frequent sun exposure. Being aware of UV levels helps in making informed decisions about sun protection, significantly reducing the risk of sunburn and promoting long-term skin health. With midday UV Index values soaring to 12, knowing when to seek shade or apply sunscreen can mean the difference between a fun day outdoors and a painful, sun-damaged experience. With Tosa's intense UV levels, it’s essential to stay informed and protect your skin while enjoying the beauty of this vibrant city.
The UV Index data reveals a notable progression in sun exposure throughout the day. Starting at a modest 2 at 7:00 AM, it quickly escalates, peaking at a striking 12 by noon, indicating a high risk for harm from unprotected sun exposure. As the afternoon unfolds, the index gradually recedes, dropping to 9 at 2:00 PM and further decreasing to 1 by 7:00 PM. This pattern suggests that the sun’s intensity is at its most dangerous during the late morning and early afternoon, emphasizing the importance of sunscreen and protective measures during these critical hours. Stay safe under the sun!
| Time | UVI | Category | Time to Burn |
|---|---|---|---|
| 07:00 | 2 | low | 45 min |
| 08:00 | 3 | 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 | 0 | 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 |