Last updated: August 1, 2025
Understanding the UV Index in Sakai-nakajima, Japan, is crucial for maintaining skin health and preventing sunburn, especially as the region experiences significant UV exposure throughout the day. During peak hours, such as from 10:00 AM to 12:00 PM, the UV Index skyrockets to 11, indicating extreme conditions that can lead to serious skin damage. With its humid subtropical climate, Sakai-nakajima sees a mix of sunny days and intense UV radiation, so monitoring UV levels is essential for outdoor enthusiasts and families alike. By staying informed about UV Index fluctuations, residents can enjoy the beautiful weather while safeguarding their skin against harmful effects.
The hourly UV Index reveals a dynamic rise and fall of sun intensity throughout the day. Starting at a mild 2 at 07:00, the index climbs steadily, reaching a peak of 11 at both 11:00 and 12:00, indicating a high risk of harm from unprotected sun exposure. As the afternoon sun begins to descend, the index tapers off to 9 at 13:00, then gradually decreases to 5 by 15:00. By 16:00, it drops to 3, signaling the end of peak sun strength, while cool evenings arrive with a return to 1 at both 17:00 and 18:00. Finally, at 19:00, the UV Index hits 0, marking a safe transition into the night. Stay protected during the day's brightest hours!
| Time | UVI | Category | Time to Burn |
|---|---|---|---|
| 07:00 | 2 | low | 45 min |
| 08:00 | 4 | moderate | 30 min |
| 09:00 | 7 | 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 | 9 | very high | 15 min |
| 14:00 | 7 | high | 25 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, UV levels demonstrate significant seasonal variations, with high-risk months typically occurring from March through August. During this period, the UV Index peaks at 11 in June, July, and August, marking it as an extreme risk category with a burn time of just 10 minutes. In contrast, the lowest UV Index readings, categorized as moderate, occur in January, February, November, and December, allowing for 30-minute exposure without immediate risk of skin damage. Visitors and residents should prioritize sun safety measures, particularly in the high-risk months—using sunscreen, wearing protective clothing, and seeking shade during peak hours to minimize potential harm from intense UV radiation.
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 |
| Sakai-nakajima | 3 | 5 | 8 | 9 | 10 | 11 | 11 | 11 | 9 | 7 | 5 | 3 |
| 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 |