Last updated: July 2, 2025
Understanding the UV Index in Usuki, Japan, is crucial for safeguarding your skin from harmful ultraviolet rays. With peak UV levels reaching an impressive 12 during midday, awareness of these levels is essential for preventing sunburn and promoting overall skin health. This coastal region, characterized by its Cfa climate, experiences significant UV exposure risks, particularly during summer months. Staying informed about the UV Index not only helps you enjoy the beautiful sunny days of Usuki safely but also supports long-term skin health. Always protect yourself with sunscreen, clothing, and shade, especially when UV levels are high!
The UV Index for the day reveals a dynamic shift in sun exposure, peaking dramatically between 11:00 AM and 1:00 PM. Starting the morning with a mild maximum of 2 at 7:00 AM, the index steadily rises, reaching 12 by midday—an indication of high risk for harm from unprotected sun exposure. As the afternoon progresses, it dips to 10 at 2:00 PM and then gradually decreases to a more moderate level of 4 by 4:00 PM. By the evening, the UV Index settles back down to 1 by 6:00 PM, signaling a safe time to enjoy the outdoors again. Be sure to protect your skin during those peak hours!
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 | 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, the UV Index experiences significant fluctuations, with the highest risk months emerging from March to September. During this period, the UV Index peaks at 12, indicating an extreme exposure category from May to August, requiring only 10 minutes of sun exposure before risking skin damage. Conversely, January and December feature a moderate UV Index of 4, allowing for about 30 minutes of safe exposure. Visitors and residents are advised to take extra precautions during high-risk months, such as wearing sunscreen, protective clothing, and seeking shade during peak hours, particularly in the summer months when the potential for sunburn is acute. As the UV Index starts to decline in October and November, a return to more moderate sun safety measures becomes appropriate.
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 |
Usuki | 4 | 6 | 9 | 11 | 12 | 11 | 12 | 12 | 11 | 7 | 6 | 4 |