Last updated: June 2, 2025
Understanding the UV Index is crucial for residents and visitors in Nagatoro, Japan, where the risk of sun exposure can fluctuate significantly throughout the day. With peak UV levels reaching up to 11 during midday hours, being aware of these levels is essential for preventing sunburn and safeguarding your skin health. Nagatoro's Cfa climate brings warm summers, making it vital to monitor UV exposure risks associated with outdoor activities. Stay informed and protect yourself against harmful rays as you explore this beautiful region!
As the sun rises, the UV Index begins to climb, starting at a mild 3 at 07:00. By 08:00, it reaches a moderate 5, signaling that it's time to start thinking about sun protection. The intensity peaks at 11 from 11:00 to 12:00, marking the highest risk period of the day. As the afternoon progresses, the UV Index gradually declines, dropping to 8 at 14:00 before dwindling to 5 by 15:00. As the day winds down, the index continues to fall, hitting a low of 1 from 16:00 to 18:00, and finally reaching 0 after 19:00. It’s essential to stay vigilant and take precautions during the peak hours to enjoy the sunshine safely!
| 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 | 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 demonstrates notable seasonal changes, with the most intense exposure occurring from April to August. During these months, the UV Index reaches extreme levels (10-12), significantly reducing the burn time to just 10 minutes. March and September also pose risks with very high levels (8-10), allowing for a burn time of only 15 minutes. Consequently, February and October present high levels (6-7), where protective measures are still advised with adjusted burn times of 25 minutes. Residents and visitors should exercise caution and protect their skin, especially during the high-risk months of April through August, by using sunscreen, wearing protective clothing, and limiting sun exposure during peak hours.
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 |
| Nagatoro | 4 | 6 | 8 | 10 | 11 | 11 | 12 | 11 | 10 | 7 | 5 | 4 |