Last updated: June 2, 2025
Understanding the UV Index is essential for residents and visitors of Naze, Japan, where the subtropical Cfa climate brings both beauty and risks associated with high sun exposure. As UV levels can spike dramatically, peaking at a dangerous 13 around midday, being aware of these fluctuations is crucial for preventing sunburn and promoting overall skin health. Whether you are exploring the scenic landscapes or enjoying outdoor activities, knowing the UV Index enables you to take precautionary measures against harmful rays, ensuring a safe and enjoyable experience under the Japanese sun.
Today’s UV index paints a clear picture of the sun's intensity throughout the day, starting mildly at 1 at 7 AM. As the morning progresses, the index rises steadily, reaching 3 by 8 AM and 6 by 9 AM. The sun reaches its peak heat around 12 PM, where the UV index hits a maximum of 13—a strong reminder to take precautions. As the afternoon unfolds, the levels gradually drop, with 10 at 2 PM and decreasing to 5 by 4 PM. By the evening, the index falls back to a tranquil 1 by 7 PM, signaling a return to a safer sun exposure threshold. Remember to stay protected during those peak hours!
| Time | UVI | Category | Time to Burn |
|---|---|---|---|
| 07:00 | 1 | low | 45 min |
| 08:00 | 3 | moderate | 30 min |
| 09:00 | 6 | high | 25 min |
| 10:00 | 9 | very high | 15 min |
| 11:00 | 11 | extreme | 10 min |
| 12:00 | 13 | extreme | 10 min |
| 13:00 | 12 | extreme | 10 min |
| 14:00 | 10 | very high | 15 min |
| 15:00 | 8 | very high | 15 min |
| 16:00 | 5 | moderate | 30 min |
| 17:00 | 2 | low | 45 min |
| 18:00 | 1 | low | 45 min |
| 19:00 | 1 | low | 45 min |
Throughout the year, UV levels exhibit significant seasonal variations, with March to September being particularly dangerous. The highest risk months—April through August—see UV Index values reaching extreme levels (12-13), where the recommended maximum exposure time is only 10 minutes. In contrast, January and December feature high UV Index values (6) with a burn time of 25 minutes, while February and October transition to very high levels (8-9) with shorter burn times. For both visitors and residents, it is crucial to take precautionary measures during high UV index months: use broad-spectrum sunscreen, wear protective clothing, and seek shade during peak sun hours. Always monitor the UV Index to ensure safe sun exposure.
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 |
| Naze | 6 | 8 | 11 | 12 | 12 | 13 | 13 | 13 | 12 | 9 | 8 | 6 |