Last updated: June 2, 2025
Understanding the UV Index is crucial for residents and visitors of Iijima, Japan, particularly given its Dfb climate, which presents unique sun exposure risks throughout the year. As UV levels can peak at 11 during midday, it’s vital to stay informed to prevent sunburn and protect skin health. By recognizing these levels, you can take proactive measures against harmful UV radiation, ensuring you enjoy outdoor activities safely. Awareness of the UV Index in Iijima not only enhances your well-being but also helps you make informed decisions about sun protection when the sun shines its brightest.
As the sun rises, the UV Index begins at a gentle 2 at 7:00 AM, making early hours perfect for outdoor plans. However, by 8:00 AM, it ramps up to 5, signaling a need for some sun protection. The intensity peaks at 11:00 AM with a UV Index of 11, indicating extreme levels, and remains intense until 1:00 PM. From there, it gradually begins to taper down, dropping to 8 by 2:00 PM and further declining to 3 by 4:00 PM. As the day winds down, the UV Index drops to 0 by 7:00 PM, providing a cool relief from the midday sun. Stay safe and enjoy the sun wisely!
| Time | UVI | Category | Time to Burn |
|---|---|---|---|
| 07:00 | 2 | low | 45 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 | 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 | 0 | low | 45 min |
As the seasons change, so do the UV Index levels, significantly influencing sun exposure risk throughout the year. High-risk months are from March to August, when the UV Index peaks at 11 to 12, indicating extreme exposure with a burn time as short as 10 minutes. Particularly critical are May and July, when the UV Index consistently reaches its maximum. Conversely, the winter months of January and December present a moderate risk with an Index of 4, allowing for a safer exposure time of 30 minutes. To ensure safety, visitors and residents are advised to take precautions during high UV Index months by wearing sunscreen, protective clothing, and seeking shade, especially during midday hours when UV exposure is greatest.
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 |
| Iijima | 4 | 6 | 9 | 10 | 11 | 11 | 12 | 12 | 10 | 7 | 6 | 4 |