Last updated: May 3, 2025
Understanding the UV Index is crucial for residents and visitors in Hotaka, Japan, where the combination of a Dfb climate and high elevation can lead to significant sun exposure risks. Monitoring UV levels is essential not just for avoiding painful sunburns, but also for maintaining long-term skin health. During peak hours, especially around noon when the UV Index can reach a striking 11, it’s vital to take protective measures such as wearing sunscreen and protective clothing. With Hotaka’s stunning landscapes and outdoor activities, being informed about UV levels helps you enjoy the sun safely!
The UV Index throughout the day presents a dynamic picture of sun exposure. As early as 7:00 AM, the index starts at a mild 2, ramping up to a moderate 4 by 8:00 AM. The sun's intensity peaks around 11:00 AM and 12:00 PM with a striking 11, marking the height of caution for outdoor activities. As we move into the afternoon, the index gradually declines, dropping to 8 by 2:00 PM and further to 5 by 3:00 PM. The evening brings relief, with the UV Index decreasing to a 1 by 5:00 PM and finally hitting 0 by 7:00 PM. It’s clear that the midday hours pose the greatest risk, so sun safety measures are essential during those peak times.
| 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 | 10 | very high | 15 min |
| 14:00 | 8 | very high | 15 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, the UV Index exhibits significant seasonal changes, peaking during the summer months. The highest risk for UV exposure occurs from March through August, with May to August categorized as extreme with UV Index values reaching up to 12. This means that residents and visitors should be particularly vigilant during these months, as the burn time reduces to just 10 minutes under direct sunlight. From September to February, the UV Index decreases, with January and December considered moderate, allowing for longer exposure times of 30 minutes. It is essential to take precautions such as wearing sunscreen, protective clothing, and seeking shade, especially during the high-risk months to minimize the risk of skin damage.
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 |
| Hotaka | 4 | 6 | 9 | 10 | 11 | 11 | 11 | 12 | 10 | 7 | 5 | 4 |