Last updated: June 2, 2025
Understanding the UV Index in Kamisu, Japan, is essential for keeping your skin healthy and protected from harmful rays. With typical UV levels peaking significantly throughout the day—reaching as high as 11 around noon—awareness of these fluctuating levels can make the difference between a fun day in the sun and painful sunburn. The Cfa climate, characterized by hot, humid summers, poses increased risks of UV exposure, particularly during the summer months. Staying informed about the UV Index empowers you to safeguard your skin, ensuring outdoor activities remain enjoyable without the burden of sun damage.
The UV Index begins its climb at 07:00 with a moderate 3, signaling a gentle start to the day. By 08:00, it escalates to 5, and as the sun reaches its zenith, the intensity peaks at an impressive 11 by 11:00 and remains constant until 12:00. This critical time urges sun enthusiasts to protect their skin, as exposure becomes significant. The afternoon brings a gradual decline, with values dropping to 9 at 13:00 and tapering off to 5 by 15:00. As the day wanes, the Index slips further, landing at 1 by 17:00, signaling a safer time to enjoy outdoor activities. As twilight approaches, the UV threat diminishes, ultimately reaching a 0 by 19:00. Enjoy the sun wisely!
| 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 | 10 | very high | 15 min |
| 11:00 | 11 | extreme | 10 min |
| 12:00 | 11 | extreme | 10 min |
| 13:00 | 9 | 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 | 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 |