Last updated: July 2, 2025
Understanding the UV Index is crucial for residents and visitors of Tomari, Japan, where exposure to harmful ultraviolet rays can significantly impact your health. With its Dfb climate, Tomari experiences distinct seasonal variations, making it essential to monitor UV levels, especially during summer months when they can peak as high as 9 around midday. By keeping track of the UV Index, you can effectively prevent sunburn and safeguard your skin health, allowing you to enjoy the beautiful outdoors without worry. Stay informed and protect yourself against the UV risks prevalent in this picturesque coastal town!
As the sun rises, the UV Index slowly climbs, starting at a gentle 2 by 07:00. By 08:00, it reaches 4, signaling it’s time to start protecting your skin. The intensity peaks around 11:00 and 12:00, hitting a maximum of 9, reminding everyone to seek shade and wear sunscreen. As the afternoon progresses, the index drops: it gently descends to 7 at 14:00, and continues its decline to 5 by 15:00. The latter part of the day sees a significant drop, with the index falling to 1 from 17:00 onwards, allowing for a safer evening outdoors. Stay vigilant during those midday hours, and enjoy the sun wisely!
| 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 | 8 | very high | 15 min |
| 11:00 | 9 | very high | 15 min |
| 12:00 | 9 | very high | 15 min |
| 13:00 | 8 | very high | 15 min |
| 14:00 | 7 | high | 25 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 | 1 | low | 45 min |
Throughout the year, the UV Index reflects significant seasonal changes that impact exposure risks. January and December have low UV levels (Index 2), where burn times extend to 45 minutes. As spring approaches, by March the Index rises to 5, indicating moderate exposure risk. However, from April to September, the UV Index reaches high to very high levels, peaking at 10 in August, with burn times decreasing sharply to just 15 minutes. These months—April through September—pose the highest risk for sunburn, particularly May through August when the levels are consistently very high. Visitors and residents should prioritize sun protection during these months, recommending the use of sunscreen, hats, and protective clothing, and to seek shade during peak hours to minimize UV exposure. By October and November, the UV levels drop to moderate again, allowing for safer outdoor activities.
UV Risk Categories
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Tomari | 2 | 3 | 5 | 7 | 9 | 9 | 9 | 10 | 8 | 5 | 3 | 2 |
| 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 |