Last updated: May 3, 2025
Understanding the UV Index is crucial for residents and visitors in Shiojiri, Japan, where the sun can be both a source of joy and a risk to skin health. With peak UV levels reaching as high as 11 during midday, awareness of UV exposure is essential for preventing sunburn and long-term skin damage. Shiojiri, located in a Dfb climate zone, experiences distinct seasons, but the midday sun can pose significant risks during warmer months. By staying informed about the UV Index, you can effectively protect yourself and enjoy the stunning landscapes of this beautiful region safely.
The UV Index throughout the day reveals a dramatic rise in sun intensity, peaking at 11 around 11:00 AM and 12:00 PM. Starting from 07:00 AM with a low of 2, the index escalates rapidly, reaching 10 by 10:00 AM. As the sun climbs higher, it delivers its harshest rays, prompting caution for those outdoors. From 1:00 PM onward, the index gradually declines, hitting 5 at 3:00 PM, and finally tapering off to 0 by 7:00 PM. This profile highlights the importance of sun protection during the midday hours when UV exposure is most intense. Stay safe and protect your skin! 🌞
| Time | UVI | Category | Time to Burn |
|---|---|---|---|
| 07:00 | 2 | low | 45 min |
| 08:00 | 5 | moderate | 30 min |
| 09:00 | 7 | high | 25 min |
| 10:00 | 10 | 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 |
Throughout the year, UV index levels fluctuate, with the most significant increases occurring from March to September. During these months, particularly in May, June, July, and August, the UV index reaches its peak at 12, categorized as extreme, with a burn time of just 10 minutes. March and April also present high risks, featuring very high UV levels of 9 and 10 respectively. Visitors and residents should be particularly vigilant in these high-risk months, applying sunscreen, wearing protective clothing, and seeking shade whenever possible. As UV levels decrease from late summer into fall and winter, with January and December categorized as having moderate exposure (UV index 4), precautions remain advisable to ensure skin protection year-round.
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 |
| Shiojiri | 4 | 6 | 9 | 10 | 11 | 11 | 12 | 12 | 10 | 7 | 5 | 4 |