Last updated: July 2, 2025
In Mitoyo, Japan, being aware of the UV Index is crucial for maintaining skin health and preventing sunburn. Understanding UV levels helps residents and visitors alike protect themselves from harmful ultraviolet radiation, which is particularly important in this Cfa climate zone where summer sun exposure can be intense. With midday peaks reaching as high as 12 on the UV Index scale, it's essential to be informed about the varying levels throughout the day to minimize risks and enjoy outdoor activities safely under the sun.
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 |
From January to December, UV Index values exhibit significant seasonal changes, peaking during the summer months. January and December maintain a moderate UV Index of 4, allowing for a burn time of 30 minutes. As spring arrives, March sees a notable increase to 8 (very high), reducing burn time to 15 minutes. The peak UV exposure occurs from May through August, where the index reaches a maximum of 12 (extreme), necessitating a burn time as brief as 10 minutes. September begins a gradual decline, returning to a very high level of 10, while October and November drop to moderate levels at 5. Visitors and residents should exercise caution from March to August, particularly during these high-risk months, by wearing protective clothing, applying sunscreen frequently, and seeking shade to limit UV exposure.
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 |
Mitoyo | 4 | 5 | 8 | 10 | 11 | 11 | 12 | 12 | 10 | 7 | 5 | 4 |
Osaka UVI | 4 | 6 | 8 | 11 | 11 | 11 | 12 | 11 | 10 | 7 | 5 | 3 |