Last updated: June 2, 2025
In Masaki-cho, Japan, understanding the UV Index is crucial for protecting your skin and overall health. With UV levels peaking at 11 during midday hours, being aware of these rates can help prevent sunburn and long-term skin damage. The region's Cfa climate brings warm summers, enhancing the risk of high UV exposure. By keeping an eye on the UV Index, you can enjoy the beautiful outdoors safely while minimizing the harmful effects of the sun’s rays. Stay informed and safeguard your skin!
The hourly UV Index showcases a dynamic rise and fall throughout the day, peaking spectacularly around 11:00 AM and 12:00 PM, both hitting a maximum of 11, indicating a high risk of harm from unprotected sun exposure. As the day progresses, it starts at a gentle 2 at 07:00 AM, providing a calm introduction to the sun's intensity. By 9:00 AM, it reaches a moderate 6, and then scales up to its highest point by 10:00 AM with a reading of 9. As afternoon approaches, the index begins its decline, dropping to 6 at 15:00 PM before further easing into the evening with a 2 at 17:00 PM. By 18:00 PM and 19:00 PM, the UV levels settle at a safe 1, offering relief from the midday sun's intensity, making the late afternoon and evening much more inviting for outdoor activities. Stay sun-safe!
| 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 | 11 | 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 |
The UV Index shows significant seasonal changes, with the highest levels of ultraviolet radiation occurring from March to September, characterized by very high to extreme exposure categories. March and April see UV Index values ranging from 9 to 10, while May through August peak at 12, indicating an extreme risk of harm from unprotected sun exposure, with a notably short burn time of just 10 minutes. July and August are particularly high-risk months, necessitating careful sun protection measures. As the months progress toward October, there is a decrease to 8, moving back to very high levels, while November and December return to high and moderate levels, respectively. To ensure safety, visitors and residents are strongly advised to adopt protective measures, such as using sunscreen, wearing protective clothing, and seeking shade during peak sun hours, particularly during the high-risk months of May through September.
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 |
| Masaki-cho | 4 | 6 | 9 | 10 | 12 | 11 | 12 | 12 | 11 | 8 | 6 | 4 |