Last updated: May 3, 2025
Awareness of the UV Index is crucial for residents and visitors in Ishikari, Japan, where the unique Dfb climate brings varied sun exposure throughout the year. Understanding the daily UV levels is essential for preventing sunburn and promoting long-term skin health, as higher indices can lead to greater risks, especially during peak hours. With UV levels peaking at 9 around midday, Ishikari’s residents should take precautions against overexposure to harmful rays, ensuring a safe and enjoyable time outdoors while basking in the beautiful Japanese landscape.
The UV Index (UVI) starts the day at a mild level of 2 at 7:00 AM, gradually climbing to a peak of 9 by 11:00 AM, signaling a strong need for sun protection. As the day progresses to 12:00 PM, it dips slightly to 8, maintaining a high risk of UV exposure. Early afternoon sees the UVI begin to lower, reaching 7 at 1:00 PM and tapering off to 4 by 3:00 PM. As daylight wanes, the index drops to 2 by 4:00 PM, before settling at a minimal 1 in the evening hours, providing a welcome relief as the sun sets at 7:00 PM, where the UVI finally falls to 0. Be sure to take precautions during the peak hours to safeguard your skin!
| 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 | 8 | very high | 15 min |
| 11:00 | 9 | very high | 15 min |
| 12:00 | 8 | very high | 15 min |
| 13:00 | 7 | high | 25 min |
| 14:00 | 6 | high | 25 min |
| 15:00 | 4 | 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 |
Throughout the year, the UV Index experiences notable seasonal changes, indicating varying levels of sun exposure risk. The high-risk months typically occur from May to August, when the UV Index reaches very high levels (9-10), warranting caution as the burn time decreases to just 15 minutes. In contrast, the winter months of December and January present a much lower risk, with UV indexes of 2 and burn times extending to 45 minutes. Visitors and residents are advised to take appropriate precautions during the high-risk months, such as wearing protective clothing, applying broad-spectrum sunscreen, and seeking shade during peak sun hours to minimize potential skin damage. For the moderate months of February, April, October, and November, it’s important to remain aware of UV exposure and adjust outdoor activities accordingly.
UV Risk Categories
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Ishikari | 2 | 3 | 6 | 7 | 9 | 9 | 9 | 10 | 8 | 5 | 3 | 2 |
| 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 |