Last updated: August 1, 2025
Understanding the UV Index is crucial for residents and visitors in Ureshinomachi-shimojuku, Japan, where moderate to high UV levels can pose significant risks to skin health. With its Cfa climate, characterized by humid summers and mild winters, awareness of UV exposure is vital to prevent sunburn and long-term skin damage. During peak hours, especially between 10 AM and 2 PM, the UV Index can soar to dangerous levels, reaching up to 12—a clear reminder to protect yourself with sunscreen, clothing, and shade. Stay informed and enjoy the beautiful outdoor experiences Ureshinomachi-shimojuku has to offer while safeguarding your skin’s health!
The UV Index provides a clear snapshot of sun exposure throughout the day, peaking at 12 around noon. Starting the morning at a mild level of 1 at 07:00, the index swiftly climbs, reaching 11 by 11:00. The intensity plateaus at its highest point of 12 between 12:00 and 13:00, indicating a critical time for sun safety. As the afternoon progresses, the UVI declines, dropping to 10 at 14:00, and gradually softening to 4 by 16:00. By the evening hours, the index falls back to a comfortable 1 by 18:00, making later hours more forgiving for outdoor activities. Stay protected and plan your sun exposure wisely!
| Time | UVI | Category | Time to Burn |
|---|---|---|---|
| 07:00 | 1 | low | 45 min |
| 08:00 | 3 | moderate | 30 min |
| 09:00 | 5 | moderate | 30 min |
| 10:00 | 8 | very high | 15 min |
| 11:00 | 10 | very high | 15 min |
| 12:00 | 12 | extreme | 10 min |
| 13:00 | 11 | extreme | 10 min |
| 14:00 | 10 | very high | 15 min |
| 15:00 | 7 | high | 25 min |
| 16:00 | 4 | moderate | 30 min |
| 17:00 | 2 | low | 45 min |
| 18:00 | 1 | low | 45 min |
| 19:00 | 1 | low | 45 min |
The UV Index experiences significant fluctuations throughout the year, with the highest levels occurring from May to September, where it peaks at an extreme level of 12 in both July and August. This period marks the high-risk months for sun exposure, with a critical burn time of just 10 minutes. Conversely, the UV levels are more moderate in January and December, with a UV Index of 4 and a longer burn time of 30 minutes. Residents and visitors are advised to take proactive sun safety measures, particularly during the spring and summer months, including wearing sunscreen, protective clothing, and seeking shade during peak hours when the UV Index is highest.
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 |
| Osaka UVI | 4 | 6 | 8 | 11 | 11 | 11 | 12 | 11 | 10 | 7 | 5 | 3 |
| Ureshinomachi-shimojuku | 4 | 6 | 8 | 10 | 11 | 11 | 12 | 12 | 11 | 7 | 6 | 4 |