Last updated: August 1, 2025
Understanding the UV Index is crucial for residents of Hamura, Japan as it plays a vital role in sun safety and skin health. With the climate characterized by warm summers, knowing the UV levels helps prevent sunburn and reduces long-term skin damage. The UV Index in Hamura peaks between 10:00 AM and 1:00 PM with values reaching as high as 11, posing significant risks during these hours. Staying informed about these levels is essential for enjoying outdoor activities while protecting your skin from harmful UV radiation.
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 | 6 | high | 25 min |
| 10:00 | 9 | 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 | 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, seasonal changes in UV Index reveal significant variations in sun exposure risk. The high-risk months for UV exposure are predominantly from March to August, with the peak occurring in May, June, July, and August, where the UV Index reaches 11, categorized as extreme with a burn time of just 10 minutes. During this period, individuals are strongly advised to take precautions such as wearing sunscreen, protective clothing, and seeking shade, especially between 10 AM and 4 PM, when UV radiation is at its strongest. In contrast, the UV Index indicates moderate levels in January, November, and December, and high levels in October and February—months where sun safety should still be observed, though the urgency is somewhat reduced.
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 |
| Hamura | 4 | 6 | 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 |