Last updated: June 2, 2025
Understanding the UV Index is crucial for residents and visitors in Okinawa, Japan, where the warm, tropical climate brings with it a heightened risk of ultraviolet radiation exposure. With UV levels soaring to a high of 13 during peak midday hours, awareness is essential for preventing sunburn and protecting overall skin health. Just as Okinawa is known for its beautiful beaches and outdoor lifestyle, it also presents unique challenges regarding UV exposure. Stay informed and take proactive measures to enjoy the sun safely!
As the sun rises on this radiant day, the UV Index begins its ascent, starting at a mild 1 at 07:00 and gradually climbing. By 09:00, it reaches 6, indicating it's time to take some precautions. The intensity peaks at 12:00 with a robust 13, making it essential to seek shade and wear protective gear. For the next hour, the UV Index holds steady at its maximum, but begins to dip as the afternoon progresses—dropping to 8 by 15:00 and further down to 1 by 19:00. This fluctuation highlights the importance of sun safety, especially during the midday hours when UV exposure is at its highest.
| Time | UVI | Category | Time to Burn |
|---|---|---|---|
| 07:00 | 1 | low | 45 min |
| 08:00 | 3 | moderate | 30 min |
| 09:00 | 6 | high | 25 min |
| 10:00 | 9 | very high | 15 min |
| 11:00 | 11 | extreme | 10 min |
| 12:00 | 13 | extreme | 10 min |
| 13:00 | 13 | extreme | 10 min |
| 14:00 | 11 | extreme | 10 min |
| 15:00 | 8 | very high | 15 min |
| 16:00 | 5 | moderate | 30 min |
| 17:00 | 2 | low | 45 min |
| 18:00 | 1 | low | 45 min |
| 19:00 | 1 | low | 45 min |
Throughout the year, the UV Index exhibits significant fluctuations, with the highest levels occurring during the late spring and summer months. From February to September, the index reaches extreme highs, particularly in March to August, where the UV Index consistently sits at 13 with a minimal burn time of 10 minutes. The high-risk months are clearly identified as March through September, when individuals should take extra precautions. In contrast, January and December see lower UV levels, categorized as high with a burn time of 25 minutes, while October and November experience very high levels (UV Index 9) but allow slightly longer exposure (15 minutes). To ensure safety, residents and visitors are strongly advised to wear protective clothing, apply sunscreen frequently, and seek shade during peak sun hours in the high-risk months.
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 |
| Okinawa | 7 | 9 | 11 | 12 | 13 | 13 | 13 | 13 | 12 | 9 | 9 | 6 |