Last updated: June 2, 2025
Understanding the UV Index is crucial for residents and visitors in Mima, Japan, especially as this region experiences a Cfa climate, characterized by warm summers and mild winters. The UV Index provides vital information about the strength of ultraviolet radiation from the sun, highlighting the risk of sunburn and long-term skin damage. With peak UV levels reaching as high as 12 around midday, being aware of these levels is essential for effective sunburn prevention and maintaining skin health. As Mima enjoys a sunny climate, understanding these UV risks will help you protect yourself and enjoy outdoor activities safely throughout the year.
The day's UV Index starts off mild, peaking at 2 by 7 AM, ideal for early morning strolls. As the sun rises, the index steadily climbs, hitting 4 by 8 AM and reaching 6 at 9 AM. By 10 AM, the intensity skyrockets to 9, and then the sun shines its brightest from 11 AM to 12 PM, where it peaks at an intense 12. The afternoon remains intense but slightly less so, with values of 11 at 1 PM and 9 at 2 PM, before tapering off to 6 at 3 PM. A gentle decline continues into the evening, bringing the index down to 3 by 4 PM, and finally settling at 1 by 6 PM, making the evening safe for outdoor activities. It's crucial to protect your skin during the peak UV hours!
| 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 | 12 | extreme | 10 min |
| 13:00 | 11 | extreme | 10 min |
| 14:00 | 9 | very high | 15 min |
| 15:00 | 6 | high | 25 min |
| 16:00 | 3 | 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 levels vary significantly, with the highest risks typically occurring in the late spring to summer months. From April through August, the UV Index reaches extreme levels of 11 to 12, indicating that even short exposure (as little as 10 minutes) can result in skin damage. The highest-risk months are April, May, June, July, and August, where it's crucial for both visitors and residents to take protective measures such as wearing sunscreen, hats, and protective clothing. As summer transitions to fall, UV levels begin to decline, with an Index of 10 in September, followed by 7 in October and 6 in November. Visitors and residents should remain vigilant, especially during these peak months, to ensure their safety and well-being under the sun. In the winter months (December and January), the UV Index drops to 4, indicating a moderate risk, allowing for longer burn times of 30 minutes.
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 |
| Mima | 4 | 6 | 8 | 11 | 11 | 12 | 12 | 12 | 10 | 7 | 6 | 4 |