Last updated: May 3, 2025
Understanding the UV Index is crucial for residents and visitors of Asahi, Japan. With its Cfa climate, the region offers warm summers and ample sunshine, making awareness of UV levels essential for preventing sunburn and safeguarding your skin health. During peak hours—especially between 11:00 AM to 1:00 PM, when the UV Index can soar to 11—the risk of skin damage significantly increases. Stay informed about the UV Index in Asahi to enjoy the sun safely while protecting yourself from potential harm.
As the sun rises, the UV Index begins a steady ascent, starting at a moderate 3 by 7:00 AM. By 8:00 AM, it climbs to 5, catching the attention of early risers. The intensity peaks dramatically at 10:00 AM, hitting a blistering 10, and remains at its highest at 11:00 AM and 12:00 PM with a value of 11. As the afternoon unfolds, the index slowly retreats, dipping to 9 at 1:00 PM and further to 7 by 2:00 PM. By the time the sun begins its descent, the numbers dwindle to 4 at 3:00 PM, and taper off to a gentle 1 by 5:00 PM, disappearing entirely by 7:00 PM. This hourly fluctuation underscores the importance of sun protection during those peak hours, especially when the UV Index soars. Remember to stay safe and shield yourself during the hottest times of the day!
| Time | UVI | Category | Time to Burn |
|---|---|---|---|
| 07:00 | 3 | moderate | 30 min |
| 08:00 | 5 | moderate | 30 min |
| 09:00 | 8 | very high | 15 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 | 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, UV exposure varies significantly, with the highest levels occurring during the summer months. From March to August, the UV Index reaches a peak of 11 during May, June, and July, classified as extreme with a burn time of just 10 minutes. Notably, April and August also present very high levels, indicative of a higher risk for skin damage. Visitors and residents are advised to take extra precautions during these months by seeking shade, wearing protective clothing, and applying sunscreen frequently. Conversely, the risk is lower in the winter months, with the UV Index ranging from 3 to 5 from January to February and returning to similar levels in November and December. Awareness of these seasonal changes is crucial to ensure appropriate sun safety measures are taken 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 |
| Asahi | 3 | 5 | 8 | 10 | 11 | 11 | 11 | 10 | 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 |