Last updated: July 2, 2025
Understanding the UV Index is crucial in China and Japan, where sun exposure can significantly impact skin health. With UV levels peaking at 13 around noon, being aware of UV risks not only helps in preventing painful sunburns but also plays a vital role in reducing long-term skin damage. China's climate is characterized by hot summers and moderate humidity, contributing to enhanced UV radiation during certain hours. By staying informed about local UV levels, residents and visitors alike can take proactive steps to enjoy the sun safely while protecting their skin.
From 07:00 to 19:00, the UV Index exhibits a pronounced peak during midday hours, soaring to 13 between 12:00 and 13:00. The intensity rises steadily from a mild 1 at 07:00 to a substantial 12 at 11:00, indicating peak sun exposure just before noon. As the afternoon progresses, the index gradually declines, dropping to 5 by 16:00 and further to a safe 1 as the sun sets. With a dramatic increase during the late morning and early afternoon, it's crucial to stay protected against UV rays, especially when the index hits 9 and above between 10:00 and 14:00.
Time | UVI | Category | Time to Burn |
---|---|---|---|
07:00 | 1 | low | 45 min |
08:00 | 3 | moderate | 30 min |
09:00 | 5 | moderate | 30 min |
10:00 | 9 | very high | 15 min |
11:00 | 12 | extreme | 10 min |
12:00 | 13 | extreme | 10 min |
13:00 | 13 | extreme | 10 min |
14:00 | 11 | extreme | 10 min |
15:00 | 8 | very high | 15 min |
16:00 | 5 | 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 |