Last updated: May 3, 2025
Understanding the UV Index is crucial for residents of Ashiya, Japan, where the sun's strength can vary dramatically throughout the day. With a temperate Cfa climate, Ashiya experiences peak UV levels that can lead to severe sunburn and long-term skin health issues if proper precautions aren't taken. For instance, during midday hours, the UV Index can soar to a staggering 11, indicating extreme exposure risk. By staying informed about daily UV levels, you can effectively protect your skin and enjoy sunny days while minimizing potential harm.
The UV Index for the day follows a dynamic trend, peaking during the midday hours. Starting at a modest 2 at 7:00 AM, the intensity gradually intensifies, reaching 4 by 8:00 AM. As the sun climbs higher, the index escalates significantly, hitting a striking 9 at 10:00 AM and reaching its zenith of 11 at 12:00 PM. After this peak, a gradual decline sets in, with the index dropping to 5 by 3:00 PM before tapering off to 1 by 5:00 PM. The day concludes with a UV Index of 0 by 7:00 PM, signaling a clear drop in potential UV exposure. It's a reminder to stay sun-smart, especially during the midday hours when the UV rays are at their strongest!
| 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 | 10 | very high | 15 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, the UV Index exhibits significant seasonal changes, indicating varying levels of sun exposure risk. The high-risk months for UV radiation are typically from March to August, where the UV Index reaches an extreme level of 11, suggesting a burn time as short as 10 minutes. Notably, April through August presents the highest risk, when protective measures are particularly crucial. As such, it is advisable for both visitors and residents to take precautions, such as wearing sunscreen, protective clothing, and seeking shade during peak hours, especially in these summer months. Conversely, during the cooler months of January, December, and November, the UV Index drops to moderate levels, allowing for more relaxed sun exposure. Overall, staying informed about the UV Index is essential for enjoying the outdoors safely 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 |
| Ashiya | 4 | 6 | 8 | 11 | 11 | 11 | 11 | 11 | 10 | 7 | 5 | 3 |
| Osaka UVI | 4 | 6 | 8 | 11 | 11 | 11 | 12 | 11 | 10 | 7 | 5 | 3 |