Last updated: May 3, 2025
Understanding the UV Index is crucial for residents and visitors in Tomamae, Japan, especially during the warmer months. With UV levels often peaking in the afternoon, awareness is key to preventing sunburn and maintaining skin health. The local climate, classified as Dfb, brings with it a mix of sun and cloud, making midday exposure particularly risky. A quick glance at the UV Index reveals that from 10:00 AM to 2:00 PM, levels can soar to 8, indicating a high risk of harm from unprotected sun exposure. Staying informed about these levels helps you protect your skin and enjoy the beautiful outdoors safely!
The UV Index shows a dynamic shift throughout the day, starting with a gentle maximum of 3 at 7:00 AM. As the sun rises higher, we see a gradual increase, peaking at a notable 8 between 11:00 AM and 12:00 PM. This is prime time to seek shade or apply sunscreen, as the intensity of UV rays can lead to sunburn in no time. By the early afternoon, the index starts to decline, dipping to 6 at 2:00 PM, then further to 4 by 3:00 PM. After that, a steady drop occurs, plunging to a safe 0 by 7:00 PM. It’s crucial to stay vigilant during those peak hours to protect your skin!
| Time | UVI | Category | Time to Burn |
|---|---|---|---|
| 07:00 | 3 | moderate | 30 min |
| 08:00 | 4 | moderate | 30 min |
| 09:00 | 6 | high | 25 min |
| 10:00 | 7 | high | 25 min |
| 11:00 | 8 | 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 variations. January and December mark the lowest UV levels, categorized as low, with a burn time of 45 minutes. As spring approaches, both February and March see an increase to moderate levels, indicating a burn time of 30 minutes. The UV Index peaks in the summer months of May through August, reaching very high levels (UV Index 8-9) with a significantly reduced burn time of just 15 minutes. As autumn sets in, September returns to a high exposure category, allowing for a 25-minute burn time, while October and November shift back to moderate. Given these fluctuations, it’s crucial for visitors and residents to take precautions during the high-risk months of May through August, including seeking shade, wearing protective clothing, and applying sunscreen to prevent skin damage.
UV Risk Categories
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Tomamae | 2 | 3 | 5 | 7 | 8 | 9 | 9 | 9 | 7 | 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 |