Last updated: May 3, 2025
Understanding the UV Index is crucial for residents and visitors in China and Japan, where sun exposure can lead to serious health risks. The UV levels typically peak around midday, reaching a maximum of 13, indicating an extreme risk for sunburn and long-term skin damage. In these regions, characterized by a humid subtropical climate (Cfa), awareness of the UV Index helps you take necessary precautions to protect your skin while enjoying the outdoors. By knowing when to seek shade, apply sunscreen, or wear protective clothing, you can effectively safeguard your skin health and enjoy the sunny days safely.
The UV Index for the day exhibits a striking daytime peak, rising steadily from a gentle 1 at 07:00 to an intense 13 by 12:00. As the sun reaches its zenith, the 11:00 and 12:00 hours warn of heightened exposure, with the index hitting its maximum at 13:00 before beginning its gradual decline. By 15:00, it slips to 7, reminding us that even in the afternoon, protection is vital. As the day winds down, the UV levels fall back to a safe 1 by 18:00, ensuring a return to safer conditions for evening activities. Stay vigilant and protect your skin during those midday hours!
Time | UVI | Category | Time to Burn |
---|---|---|---|
07:00 | 1 | 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 | 13 | extreme | 10 min |
13:00 | 12 | extreme | 10 min |
14:00 | 10 | very high | 15 min |
15:00 | 7 | 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, UV exposure varies significantly, with the highest risk months occurring from March to September, where the UV Index remains extreme at 11 to 13. Residents and visitors should be particularly vigilant during this period, as the burn time is reduced to just 10 minutes. February also presents a high risk, with an index of 8, while October and November maintain very high levels, advising burn times of 15 minutes. As UV levels fluctuate, individuals should take precautions, such as wearing protective clothing, applying sunscreen regularly, and seeking shade during peak sun hours, especially in the high-risk months of March through September. January and December offer some relief with a high UV Index but longer burn times of 25 minutes. Staying informed about these changes can help ensure safe and enjoyable outdoor activities 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 |
China | 7 | 8 | 11 | 12 | 13 | 13 | 13 | 13 | 13 | 9 | 8 | 6 |