Last updated: July 2, 2025
Understanding the UV Index in Hakuba, Japan, is essential for safeguarding your skin and overall health. As a popular destination known for its stunning ski resorts and outdoor adventures, awareness of UV levels is critical, particularly during sunny days when the risk of sunburn increases dramatically. With the region's Dfb climate, you can expect fluctuating UV exposure throughout the year, peaking around midday with indices reaching as high as 11. By knowing the UV Index, you can take proactive steps to protect yourself from harmful UV rays, ensuring that your time in Hakuba is safe and enjoyable.
The UV Index throughout the day paints a vivid picture of sun intensity. It begins with a mild reading of 2 at 07:00, gradually rising to a moderate 4 by 08:00. As the sun reaches its peak, the index surges to a striking 9 at 10:00, hitting a maximum of 11 at both 11:00 and 12:00—a clear indication to seek shade or apply sunscreen. The intensity then begins to dip, falling to 10 at 13:00, before gradually decreasing to 8 at 14:00. By 15:00, the index declines to 5, and as evening approaches, it settles at 2 by 17:00, before tapering off to 1 at 18:00 and finally reaching 0 at 19:00. This hourly trend highlights the importance of midday sun protection, ensuring a safe and enjoyable outdoor experience.
| 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 | 2 | low | 45 min |
| 18:00 | 1 | low | 45 min |
| 19:00 | 0 | low | 45 min |
Throughout the year, UV exposure experiences significant variation, with the highest risks occurring during the spring and summer months. Notably, March to August sees an escalated UV Index, peaking at 11 from May through August, corresponding to an extreme category with a burn time of just 10 minutes. These months are particularly critical for minimizing sun exposure; residents and visitors should take extra precautions, such as wearing protective clothing, applying sunscreen, and seeking shade during peak hours. As summer transitions to fall, the UV index gradually decreases, with September and October still presenting very high and high risks, respectively. The safer months of November and December return to a moderate risk level, reminding everyone to remain vigilant about sun safety year-round.
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 |
| Hakuba | 4 | 6 | 9 | 10 | 11 | 11 | 11 | 11 | 10 | 7 | 5 | 4 |
| Osaka UVI | 4 | 6 | 8 | 11 | 11 | 11 | 12 | 11 | 10 | 7 | 5 | 3 |