Last updated: June 2, 2025
In Ako, Japan, being aware of the UV Index is essential for safeguarding your skin and promoting overall health. The UV Index measures the strength of ultraviolet radiation from the sun, and understanding these levels can help you prevent sunburn and long-term skin damage. With a Cfa climate that brings warm summers and ample sunshine, residents and visitors often face heightened UV exposure risks, especially during midday hours when values can soar to 11. By staying informed about the UV Index in Ako, you can enjoy the outdoors while protecting your skin effectively.
The UV Index data reveals a clear pattern in solar exposure throughout the day. Morning rays begin gently, with a maximum of 2 at 07:00, steadily rising to 4 by 08:00. As the sun climbs higher, the index peaks at an impressive 11 at 12:00, indicating a moment of intense UV radiation. Temperatures remain elevated with a 10 at 11:00 and 13:00, before gradually declining to 8 by 14:00. The afternoon light softens, dropping to 6 by 15:00, then continues to retreat as the sun sets—falling to 3 at 16:00, 2 at 17:00, and reaching 1 by 18:00 and 19:00. This data underscores the importance of protecting your skin during the peak hours, especially between 10:00 and 14:00, when the UV Index is at its highest.
| 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 | 8 | 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 | 6 | high | 25 min |
| 16:00 | 3 | moderate | 30 min |
| 17:00 | 2 | low | 45 min |
| 18:00 | 1 | low | 45 min |
| 19:00 | 1 | low | 45 min |
Throughout the year, the UV index experiences significant fluctuations, indicating varying levels of sun exposure risk. High-risk months are primarily from March to September, where UV indexes peak at 11 or 12, signaling extreme exposure levels and necessitating caution. Residents and visitors should be particularly vigilant during these months, with recommended burn times dropping to as low as 10 minutes in peak summer months. In contrast, the winter months of January, February, November, and December see moderate UV levels (index 4-5), with more manageable burn times of 30 minutes. To ensure safety, it’s advisable for individuals to wear protective clothing, apply sunscreen, and seek shade during peak UV hours, especially from late spring through early fall.
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 |
| Ako | 4 | 5 | 8 | 11 | 11 | 11 | 12 | 11 | 10 | 7 | 5 | 4 |
| Osaka UVI | 4 | 6 | 8 | 11 | 11 | 11 | 12 | 11 | 10 | 7 | 5 | 3 |