Last updated: August 1, 2025
Understanding the UV Index in Soka, Japan is crucial for safeguarding your skin health, especially given the region's Cfa climate, which can lead to elevated UV exposure during the sunnier months. The UV Index, which ranges significantly throughout the day—peaking at 11 around noon—serves as a key indicator for sunburn risk and long-term skin damage. By keeping an eye on the UV levels, you can take the necessary precautions to enjoy the sunlight safely, whether that's applying sunscreen, wearing protective clothing, or limiting sun exposure during peak hours. With Soka's vibrant summers, being informed about UV levels not only contributes to sunburn prevention but also promotes overall skin health.
As the sun rises, the UV Index begins its climb, starting at a modest 2 at 7:00 AM. By 8:00 AM, it gains momentum, reaching 4, but the real peak arrives between 10:00 AM and 12:00 PM, where it soars to a striking 11. This is the time to seek shade or wear protective gear, as the sun's rays are at their harshest. After noon, the intensity wanes slightly with readings of 10 at 1:00 PM and gently dropping to 8 by 2:00 PM. As the afternoon turns to evening, the index cools down to 5 at 3:00 PM, before dipping to 3 by 4:00 PM, and ultimately settling at 1 by 6:00 PM. By sunset, the danger fades, leaving a 0 UV reading at 7:00 PM. Keep an eye on the UV Index to enjoy the sun safely!
| 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 | 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 | 5 | 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 |
As the seasons change, the UV Index fluctuates significantly, influencing the risk of sun exposure throughout the year. January and February start with a moderate UV Index of 3 and 5, allowing for a burn time of 30 minutes. However, by March, the UV Index jumps to 8, which is categorized as very high, reducing safe exposure to just 15 minutes. The peak months for UV radiation are May through August, where the Index reaches an extreme level of 11, necessitating a mere 10 minutes of exposure before risking sunburn. September begins a gradual decline to a very high index of 10, while October and onward return to moderate levels. Visitors and residents should be particularly cautious from March to August—wearing protective clothing, applying sunscreen, and seeking shade to minimize UV damage during these high-risk months.
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 |
| Soka | 3 | 5 | 8 | 9 | 11 | 11 | 11 | 11 | 10 | 7 | 5 | 4 |
| 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 |