Last updated: June 2, 2025
In Sapporo, Japan, staying aware of the UV Index is crucial for protecting your skin and overall health. Understanding UV levels not only helps prevent painful sunburns but also plays a vital role in reducing the risk of long-term skin damage. Sapporo's Dfb climate brings a moderate mix of warmth and sunshine, yet UV exposure can peak during midday hours, reaching levels as high as 9 between 11:00 AM and 1:00 PM. With this knowledge, residents and visitors can take proactive measures to enjoy the outdoors safely while safeguarding their skin against harmful UV rays.
As the sun rises, the UV Index (UVI) begins its ascent, reaching a moderate level of 3 by 7:00 AM. From there, it rapidly climbs, hitting 5 at 8:00 AM, followed by a sharp increase to 7 by 9:00 AM. The peak occurs between 11:00 AM and 1:00 PM, where the UVI stabilizes at a high of 9, signaling the need for protective measures against harmful rays. As afternoon approaches, the UVI gradually dips to 7 at 2:00 PM, before descending to a gentle 5 by 3:00 PM. The sun's intensity wanes in the late afternoon, dropping to 3 at 4:00 PM and settling into the low levels of 1 from 5:00 PM onward. As the day winds down, the UVI reflects a steady decline, reminding us of the importance of sun safety during peak hours.
| Time | UVI | Category | Time to Burn |
|---|---|---|---|
| 07:00 | 3 | moderate | 30 min |
| 08:00 | 5 | moderate | 30 min |
| 09:00 | 7 | high | 25 min |
| 10:00 | 8 | very high | 15 min |
| 11:00 | 9 | very high | 15 min |
| 12:00 | 9 | very high | 15 min |
| 13:00 | 9 | 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 | 1 | 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 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sapporo | 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 |