Last updated: May 3, 2025
Understanding the UV Index in Rumoi, Japan, is crucial for maintaining skin health and preventing sunburn. With UV levels often peaking at a high of 8 around midday, awareness of these fluctuations can help residents and visitors alike protect themselves from harmful effects of overexposure. Rumoi, located in a Dfb climate zone, experiences distinct seasonal variations that can impact UV exposure, particularly during the summer months. By staying informed about the UV Index, you can enjoy the sun safely while taking proactive steps to safeguard your skin.
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 fluctuates, indicating varying levels of sun exposure risk. January and December present the lowest UV levels (2), categorized as low, allowing for longer exposure times of 45 minutes without burning. As spring approaches, February and March see a moderate rise in UV Index (3 to 5), with a reduced burn time of 30 minutes. April marks a significant shift to a high exposure category (UV Index 7), followed by the very high category from May to September, peaking at an index of 9 during the summer months, where the burn time reduces sharply to just 15 minutes. October and November see a decline back to a moderate level (UV 5 and 3, respectively). Visitors and residents should be particularly cautious during the high-risk months of May through September, applying sunscreen regularly and seeking shade to minimize the risk of sunburn during these times of intense UV exposure.
UV Risk Categories
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Rumoi | 2 | 3 | 5 | 7 | 8 | 9 | 9 | 9 | 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 |