Last updated: June 2, 2025
Understanding the UV Index is crucial for residents and visitors of Shirahama, Japan, where the sun can shine brightly, especially during peak hours. Knowing your UV levels is essential not just for enjoying outdoor activities but also for preventing sunburn and protecting your skin health. With a climate characterized as Cfa, Shirahama experiences significant UV exposure, particularly from late morning to early afternoon when the index peaks at an intense 11. Staying informed about the UV Index empowers you to make safe choices while soaking up the sun's rays in this beautiful coastal paradise.
As the sun rises, the UV Index begins its ascent, starting at a mild 2 at 07:00. By 08:00, it climbs to 4, hinting at a brighter day ahead. The intensity peaks around 11:00 and 12:00, where it reaches an impressive 11, calling for caution as rays intensify. Midday to early afternoon (12:00 - 14:00) is the most formidable, with the index hovering around 10 and 8 before gradually descending. By 17:00, it dips back to a manageable 2, and as evening sets in, the sun's grip fades, dropping to 0 by 19:00. This dynamic pattern highlights the necessity of sun protection, especially during the peak 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 | 10 | very high | 15 min |
| 14:00 | 8 | 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 | 0 | low | 45 min |
Throughout the year, the UV Index experiences significant fluctuations, with the highest risk months occurring from March to August. During this period, the UV Index peaks at 12 in July, classifying the exposure as extreme and resulting in a burn time as short as 10 minutes. The spring transitions from moderate to very high levels in March and April, emphasizing the need for increased sun protection. By May, the index reaches its extremes, necessitating vigilant sun safety measures. Visitors and residents should take care to use sunscreen, wear protective clothing, and seek shade during peak sunlight hours, particularly from March through August, to minimize the risk of skin damage. As fall and winter approach, the index gradually declines, allowing for safer outdoor activities, but caution is still advised during high UV months in October and November.
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 |
| Shirahama | 4 | 6 | 9 | 10 | 11 | 11 | 12 | 11 | 10 | 7 | 6 | 4 |