Last updated: July 2, 2025
Understanding the UV Index is essential for the residents of Matsudo, Japan, where exposure to ultraviolet radiation can significantly impact skin health. With the city experiencing a Cfa climate, sunny days can lead to elevated UV levels, making it crucial to protect yourself against sunburn and long-term skin damage. During peak hours, the UV Index can spike as high as 11, signaling a severe risk of harm without proper precautions. By staying informed about daily UV levels, you can enjoy the beautiful Matsudo outdoors while safeguarding your skin from harmful effects.
The UV Index throughout the day presents a dynamic picture of sun exposure. As early as 7:00 AM, the index starts at a mild 2, ramping up to a moderate 4 by 8:00 AM. The sun's intensity peaks around 11:00 AM and 12:00 PM with a striking 11, marking the height of caution for outdoor activities. As we move into the afternoon, the index gradually declines, dropping to 8 by 2:00 PM and further to 5 by 3:00 PM. The evening brings relief, with the UV Index decreasing to a 1 by 5:00 PM and finally hitting 0 by 7:00 PM. It’s clear that the midday hours pose the greatest risk, so sun safety measures are essential during those peak times.
Time | UVI | Category | Time to Burn |
---|---|---|---|
07:00 | 2 | low | 45 min |
08:00 | 4 | moderate | 30 min |
09:00 | 7 | high | 25 min |
10:00 | 9 | very high | 15 min |
11:00 | 11 | extreme | 10 min |
12:00 | 11 | extreme | 10 min |
13:00 | 10 | very high | 15 min |
14:00 | 8 | very high | 15 min |
15:00 | 5 | moderate | 30 min |
16:00 | 3 | moderate | 30 min |
17:00 | 1 | low | 45 min |
18:00 | 1 | low | 45 min |
19:00 | 0 | low | 45 min |
The seasonal UV variations indicate a significant increase in UV exposure from winter to summer, with high-risk months emerging from April through August. During this period, the UV Index peaks at 11 (extreme), particularly in June, July, and August, where the burn time drops to just 10 minutes. Visitors and residents are advised to take precautionary measures during these months, such as seeking shade, wearing protective clothing, and applying sunscreen frequently. As the UV levels decrease in the fall and winter months, with indices dropping to 3 in January and December, the risk of sunburn diminishes. However, maintaining sun safety practices year-round remains essential for health and well-being.
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 |
Matsudo | 3 | 5 | 7 | 9 | 10 | 11 | 11 | 11 | 9 | 7 | 5 | 3 |
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 |