Last updated: June 2, 2025
Understanding the UV Index in Ishigaki, Japan is crucial for anyone looking to enjoy the picturesque beauty of this tropical paradise. With high UV levels, particularly between 11 AM and 1 PM, awareness of UV exposure can significantly reduce the risk of sunburn and long-term skin health issues. As part of the Cfa climate zone, Ishigaki experiences intense sunlight, making it essential to stay informed about daily UV fluctuations. By knowing when to seek shade and apply sunscreen, you can fully embrace everything this stunning island has to offer while protecting your skin from harmful rays.
As the sun rises over the horizon, the UV Index begins its climb, starting at a mild 1 at 7:00 AM. By 9:00 AM, it jumps to 5, signaling a need for some sun protection. The intensity peaks dramatically at 12:00 PM, reaching a scorching 13—the perfect reminder to seek shade and apply sunscreen! The afternoon sees a gradual decline, with the index dropping to 9 at 3:00 PM, then tapering off further to 1 by 7:00 PM. This hourly progression highlights the importance of staying vigilant during those midday hours when UV exposure is at its highest, ensuring you have a safe and enjoyable day outdoors.
| Time | UVI | Category | Time to Burn |
|---|---|---|---|
| 07:00 | 1 | low | 45 min |
| 08:00 | 2 | low | 45 min |
| 09:00 | 5 | moderate | 30 min |
| 10:00 | 8 | 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 | 9 | very high | 15 min |
| 16:00 | 5 | moderate | 30 min |
| 17:00 | 3 | moderate | 30 min |
| 18:00 | 1 | low | 45 min |
| 19:00 | 1 | low | 45 min |
The UV Index experiences significant fluctuations throughout the year, peaking during the summer months. January and February start off with UV Index values of 8 and 10 respectively, which are classified as very high, with a burn time of just 15 minutes. The real danger begins in March and continues through August, where the UV Index maintains extreme levels of 12 to 13, allowing for a minimal burn time of just 10 minutes. This indicates that exposure during these months can lead to very rapid skin damage. September and October still present high risks with an Index of 10 and 9 as the burn times begin to increase, while November and December slightly decrease in risk with UV Index values of 9 and 7, leading to burn times of 15 and 25 minutes, respectively. Visitors and residents are strongly advised to take preventive measures, such as applying sunscreen, wearing protective clothing, and seeking shade during peak sunlight hours, especially from March through August. Staying informed about the UV Index can help minimize the risks associated with sun exposure and ensure safe outdoor activities.
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 |
| Ishigaki | 8 | 10 | 12 | 12 | 12 | 13 | 13 | 13 | 13 | 10 | 9 | 7 |