Last updated: July 2, 2025
Staying informed about the UV Index is crucial for residents of Ritto, Japan, where exposure to ultraviolet radiation can significantly impact skin health and increase the risk of sunburn. By understanding daily UV levels, you can take necessary precautions to protect your skin and enjoy the beautiful outdoors safely. With a Cfa climate that typically features warm summers and moderate UV exposure, knowing when to seek shade or apply sunscreen is key. For instance, during peak hours like 11:00 AM to 1:00 PM, the UV Index can rise dramatically to levels of 11, signaling a heightened need for protection. Stay smart and shield yourself from harmful rays while soaking in the sun!
The UV Index data paints a vivid picture of the sun's intensity throughout the day. Starting at 07:00, the index is quite low at 2, but as the morning unfolds, it begins to climb sharply. By 09:00, it hits 7 and reaches its peak at 11:00 and 12:00 with an impressive 11. This suggests that exposure during these hours poses a higher risk of harm without adequate protection. As the afternoon wanes, the UV Index begins to taper off, dropping to 9 by 14:00 and decreasing further to 6 by 15:00. As the sun sets, the index returns to a safe low of 1 by 18:00 and remains there until 19:00. For sun-seekers, this data emphasizes the importance of seeking shade and wearing sunscreen during those critical mid-day hours!
| Time | UVI | Category | Time to Burn |
|---|---|---|---|
| 07:00 | 2 | low | 45 min |
| 08:00 | 4 | moderate | 30 min |
| 09:00 | 7 | high | 25 min |
| 10:00 | 9 | very high | 15 min |
| 11:00 | 11 | extreme | 10 min |
| 12:00 | 11 | extreme | 10 min |
| 13:00 | 11 | extreme | 10 min |
| 14:00 | 9 | very high | 15 min |
| 15:00 | 6 | high | 25 min |
| 16:00 | 3 | moderate | 30 min |
| 17:00 | 2 | low | 45 min |
| 18:00 | 1 | low | 45 min |
| 19:00 | 1 | low | 45 min |
Throughout the year, UV exposure varies significantly, peaking during the summer months. High-risk months for UV exposure are from March to August, when the UV Index reaches its maximum levels of 10 to 11 and the burn time is as brief as 10 minutes. Notably, May through August features extreme exposure, requiring diligent sun protection practices. As the year transitions into fall, September to November sees a decrease in UV levels, with October still posing a moderate risk. To ensure safety, visitors and residents are advised to wear protective clothing, use sunscreen, and seek shade during the peak sun hours, especially from late spring through summer when the threat of sunburn is greatest.
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 |
| Ritto | 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 |