Last updated: August 1, 2025
In Muramatsu, Japan, being aware of the UV Index is essential for safeguarding your skin and overall health. The UV Index measures the strength of ultraviolet radiation, which can lead to sunburn and dermatological issues, making it vital to know the level of UV exposure throughout the day. With a Cfa climate, Muramatsu experiences a range of UV levels, peaking at an intense 11 around noon, indicating that residents and visitors should take necessary precautions during outdoor activities, especially between 10 AM and 2 PM. Understanding these UV levels helps promote sun safety, allowing you to enjoy the beauty of Muramatsu while minimizing the risk of harmful UV effects.
The UV Index (UVI) exhibits a notable pattern throughout the day. Starting at 2 at 7:00 AM, it gradually rises, peaking at 11 by noon and 1:00 PM. This high level of UV exposure indicates that sun protection is essential during these hours. As the afternoon progresses, the UVI begins to dip, dropping to 7 by 2:00 PM and then declining further to 5 by 3:00 PM. By late afternoon, the sunlight's intensity reduces significantly, with the UVI falling to 1 by 5:00 PM and remaining minimal through 6:00 PM and 7:00 PM. This data underscores the importance of taking precautions during peak hours while enjoying the outdoors.
| 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 | 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 |
| Muramatsu | 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 |