Last updated: June 2, 2025
Understanding the UV Index in Kan'onji, Japan, is crucial for maintaining skin health and preventing sunburn, especially during the peak summer months when UV levels can soar. With the city’s humid subtropical climate (Cfa), residents and visitors alike must be aware of the potential risks posed by elevated UV exposure, particularly between 10:00 AM and 2:00 PM, when readings can peak at 11. By monitoring these levels, you can take essential precautions to protect yourself from damaging UV radiation, ensuring your outdoor activities remain enjoyable and safe.
The hourly UV Index showcases a dynamic rise and fall throughout the day, peaking spectacularly around 11:00 AM and 12:00 PM, both hitting a maximum of 11, indicating a high risk of harm from unprotected sun exposure. As the day progresses, it starts at a gentle 2 at 07:00 AM, providing a calm introduction to the sun's intensity. By 9:00 AM, it reaches a moderate 6, and then scales up to its highest point by 10:00 AM with a reading of 9. As afternoon approaches, the index begins its decline, dropping to 6 at 15:00 PM before further easing into the evening with a 2 at 17:00 PM. By 18:00 PM and 19:00 PM, the UV levels settle at a safe 1, offering relief from the midday sun's intensity, making the late afternoon and evening much more inviting for outdoor activities. Stay sun-safe!
| 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 | 9 | very high | 15 min |
| 11:00 | 11 | extreme | 10 min |
| 12:00 | 11 | extreme | 10 min |
| 13:00 | 11 | extreme | 10 min |
| 14:00 | 9 | very high | 15 min |
| 15:00 | 6 | high | 25 min |
| 16:00 | 4 | moderate | 30 min |
| 17:00 | 2 | low | 45 min |
| 18:00 | 1 | low | 45 min |
| 19:00 | 1 | low | 45 min |
Throughout the year, UV exposure varies significantly, with the highest risk occurring during the late spring and summer months. From April to August, the UV Index peaks at 11 to 12, representing an extreme exposure category, with a rapid burn time of just 10 minutes. Notably, March and September are also high-risk months, with UV Index levels of 8 and 10, respectively. To protect against harmful UV radiation, it is essential for both visitors and residents to take precautions during these peak months: seek shade, wear protective clothing, and apply broad-spectrum sunscreen regularly, especially between 10 AM and 4 PM. In contrast, during the winter months (January, December), UV levels drop to moderate, offering lower risk for skin damage, with longer burn times of 30 minutes.
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 |
| Kan'onji | 4 | 6 | 8 | 11 | 11 | 11 | 12 | 12 | 10 | 7 | 6 | 4 |