Last updated: July 2, 2025
Understanding the UV Index is crucial for residents and visitors in Okayama, Japan, where sunny days can quickly turn into sunburn risks. With a climate classified as Cfa, Okayama experiences substantial UV exposure, especially during peak hours. Awareness of UV levels is vital not only for preventing painful sunburns but also for maintaining long-term skin health. As the UV Index soars to a peak of 12 around noon, it’s essential to take appropriate precautions—such as wearing sunscreen and protective clothing—to safeguard against harmful effects. Stay informed and enjoy the beautiful weather while keeping your skin protected!
As the day unfolds, the UV Index climbs steadily, peaking at a striking 12 around noon, signaling a high risk for skin damage without protection. Early risers at 07:00 encounter a mild 2, but the intensity increases quickly, reaching 9 by 10:00 and a critical 11 by 11:00. From 12:00 to 13:00, the index holds its highest point at 12, making it essential to seek shade or apply sunscreen. After 13:00, the UV levels gradually decrease, dropping back to a manageable 4 by 16:00 and winding down to a safe 1 by 18:00. This hourly data serves as a reminder to take sun safety precautions, especially during peak hours.
| Time | UVI | Category | Time to Burn |
|---|---|---|---|
| 07:00 | 2 | low | 45 min |
| 08:00 | 4 | moderate | 30 min |
| 09:00 | 6 | high | 25 min |
| 10:00 | 9 | very high | 15 min |
| 11:00 | 11 | extreme | 10 min |
| 12:00 | 12 | extreme | 10 min |
| 13:00 | 11 | extreme | 10 min |
| 14:00 | 9 | very high | 15 min |
| 15:00 | 6 | 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 |
Throughout the year, UV exposure levels fluctuate significantly, with the highest risk months occurring from March through August, when the UV Index peaks at 11-12 and reaches an extreme exposure category, resulting in a burn time as short as 10 minutes. In contrast, the lowest risk months are January, December, and November, which present a moderate UV Index of 4-5 and allow for longer exposure times without risk of burning (30 minutes). Visitors and residents should remain vigilant during the high-risk months, employing protective measures such as sunscreen, protective clothing, and limiting direct sun exposure, especially during peak hours. It is crucial to stay aware of the changing UV Index to ensure safe enjoyment of outdoor activities year-round.
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 |
| Okayama | 4 | 6 | 8 | 11 | 11 | 11 | 12 | 12 | 10 | 7 | 5 | 4 |
| Osaka UVI | 4 | 6 | 8 | 11 | 11 | 11 | 12 | 11 | 10 | 7 | 5 | 3 |