Last updated: July 2, 2025
Understanding the UV Index is crucial for residents and visitors in Mori, Japan, where the climate offers a unique blend of beauty and sunlight. With peak UV levels ranging from 4 to 12 during the day, awareness of these values is essential for preventing sunburn and maintaining long-term skin health. Mori's Cfa climate features warm summers and ample sun exposure, which, while delightful for outdoor activities, also presents risks if UV protection measures are overlooked. Stay informed and safeguard your skin by being mindful of the UV Index—your health deserves it!
The UV Index for the day reveals a dynamic trajectory of sun intensity, peaking at 12 around noon. From the early hours, starting at 2 at 7:00 AM, the index climbs steadily, reaching 7 by 9:00 AM. As the sun reaches its zenith, the UV levels soar, hitting their maximum of 11 at 11:00 AM and remaining incredibly high at 12 from 12:00 PM to 1:00 PM. However, as the afternoon progresses, the index begins to decline, tapering down to 8 at 2:00 PM and further decreasing to 6 by 3:00 PM. By the evening, the UV Index drops significantly, settling back to 2 at 5:00 PM and finally waning to a calming zero by 7:00 PM. It's a day to stay sun-smart, especially during those peak midday hours!
| 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 | 10 | very high | 15 min |
| 11:00 | 11 | extreme | 10 min |
| 12:00 | 12 | extreme | 10 min |
| 13:00 | 10 | very high | 15 min |
| 14:00 | 8 | 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 | 0 | low | 45 min |
The UV Index experiences significant seasonal variation, with March through September being the high-risk months for sun exposure. March begins the rise with an index of 8 (very high) and only a 15-minute burn time, peaking in July with an index of 12 (extreme) and a mere 10-minute burn time. May through August consistently holds an extreme exposure category, urging increased caution during these months. As summer transitions into fall, the index gradually decreases, with October dropping to 7 (high) and 15-minute burn times for October and September, before returning to moderate levels in winter. Visitors and residents are advised to take precautions during the high-risk months by seeking shade, wearing protective clothing, and applying sunscreen regularly to minimize the risk of skin damage.
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 |
| Mori | 4 | 5 | 8 | 10 | 11 | 11 | 12 | 11 | 10 | 7 | 5 | 4 |
| Osaka UVI | 4 | 6 | 8 | 11 | 11 | 11 | 12 | 11 | 10 | 7 | 5 | 3 |