Last updated: June 2, 2025
In Motomiya, Japan, staying informed about the UV Index is crucial for protecting your skin from harmful solar radiation. Understanding the varying UV levels throughout the day helps you take essential precautions to prevent sunburn and long-term skin damage. With a Cfa climate that experiences high UV exposure—peaking at 11 around midday—it's vital to be aware of these risks and adjust your outdoor activities accordingly. By monitoring the UV Index, you can enjoy the sun responsibly while prioritizing your health.
As the day unfolds, the UV Index (UVI) rises sharply, peaking at a brisk 11 between 11:00 AM and 12:00 PM. Starting from an early 3 at 7:00 AM, the index steadily climbs, highlighting the sun's increasing strength. By 9:00 AM, it reaches 7, progressing to 9 at 10:00 AM. As midday approaches, it's essential to take precautions, as UVI levels above 10 indicate a high risk of harm from unprotected sun exposure. The intensity lessens in the afternoon, dropping to 5 by 3:00 PM before gradually tapering off to 1 by 5:00 PM and beyond, when the sun's rays become less threatening. Be mindful of peak hours and ensure you're protected to enjoy the bright daylight safely!
| Time | UVI | Category | Time to Burn |
|---|---|---|---|
| 07:00 | 3 | moderate | 30 min |
| 08:00 | 5 | 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 |
As the seasons change, so does the UV Index, which measures the strength of ultraviolet radiation. January and December start the year with a moderate UV Index of 3, allowing for a safer 30-minute exposure without significant risk. Moving into February, the index rises to 5, maintaining a moderate level, but caution is advised. By March, the UV Index escalates to 7 (high), warning of a 25-minute burn time. The most critical months for UV exposure are April through August, where the UV Index peaks at 11 (extreme), significantly lowering burn times to just 10 minutes in June, July, and August. September sees a drop to 9 (very high) with a 15-minute burn time, while October and November return to moderate levels, with indices of 6 and 5 respectively, allowing for longer exposure again. Therefore, visitors and residents should take precautions, particularly from April through August, using sunscreen, wearing protective clothing, and seeking shade to minimize UV exposure during these high-risk months.
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 |
| Motomiya | 3 | 5 | 7 | 9 | 10 | 11 | 11 | 11 | 9 | 6 | 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 |