Last updated: August 1, 2025
Understanding the UV Index in Kamisu, Japan is crucial for protecting your skin from harmful ultraviolet rays. With the climate classified as Cfa, residents and visitors alike face varying UV exposure risks throughout the day. Awareness of UV levels is key to preventing sunburn and maintaining overall skin health, especially during peak hours when the index reaches a maximum of 11 around midday. As the sun rises, so does the intensity of UV rays, peaking between 10:00 AM and 1:00 PM — a reminder to always take proactive sun protection measures during these hours. Stay informed and safeguard your skin in Kamisu’s vibrant sun!
As the day unfolds, the UV Index begins to climb, starting at a mild 2 by 07:00. By 08:00, it ascends to a moderate 5, indicating that sun protection becomes essential. The intensity peaks at 11 between 11:00 and 12:00, marking the hours when solar radiation is most potent. Following this peak, the index gradually declines; it drops to 10 at 13:00, before descending to 7 by 14:00. The afternoon sees a further decrease, with readings of 5 at 15:00 and 3 at 16:00—perfect for those wishing to enjoy the sun while still being cautious. By 17:00, the index falls to a mild 1, and as the day winds down, it reaches 0 by 19:00, signaling a retreat from the sun's harmful rays. It’s crucial to stay informed and protect your skin during peak UV 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 | 9 | very high | 15 min |
| 11:00 | 10 | very high | 15 min |
| 12:00 | 10 | very high | 15 min |
| 13:00 | 9 | very high | 15 min |
| 14:00 | 7 | high | 25 min |
| 15:00 | 4 | moderate | 30 min |
| 16:00 | 2 | low | 45 min |
| 17:00 | 1 | low | 45 min |
| 18:00 | 1 | low | 45 min |
| 19:00 | 0 | low | 45 min |
Throughout the year, the UV Index experiences significant fluctuations, indicating varying levels of sun exposure risk for visitors and residents. From January to February, the UV Index ranges from 3 to 5, categorized as moderate, allowing for a relatively safe burn time of 30 minutes. As spring approaches in March, the index rises to 7 (high), with a burn time decreasing to 25 minutes. The most critical months for sun exposure are April to July, where the UV Index peaks at 11, classified as extreme, resulting in a burn time of only 10 minutes. In August and September, the risk remains high, with indexes at 10 and 9, respectively; however, burn times slightly increase to 15 minutes. As temperatures cool in October through December, the UV Index returns to moderate levels, minimizing the burn time back to 30 minutes by year-end. Visitors and residents are advised to take extra precautions during the high-risk months of April through July, such as wearing protective clothing, using sunscreen, and limiting sun exposure during peak hours to mitigate the risk of sunburn and 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 |
| Kamisu | 3 | 5 | 7 | 9 | 11 | 11 | 11 | 10 | 9 | 7 | 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 |