Last updated: July 2, 2025
In Surabaya, Indonesia, being aware of the UV Index is vital for ensuring your skin health and preventing sunburn. With a tropical climate characterized by intense sunlight, understanding the daily UV levels can protect you from overexposure and its harmful effects. As the UV Index peaks at an alarming 11 during midday hours, knowledge of these levels empowers residents and visitors alike to take necessary precautions throughout the day. Whether you're enjoying the vibrant beaches or exploring local attractions, knowing when to apply sunscreen or seek shade can make all the difference in maintaining healthy skin under the sun.
As the sun rises, the UV Index climbs steadily, starting at a gentle 1 at 7:00 AM. By 8:00 AM, it reaches 3, marking the beginning of increased sun exposure. The day continues to heat up, with the index peaking at a remarkable 11 from 11:00 AM to 12:00 PM, indicating a high risk for harm from unprotected sun exposure. As the afternoon sets in, it gradually declines, dropping to 6 by 2:00 PM and subsequently to 3 by 3:00 PM. As the sun begins to descend, the index returns to a safer 1 by 4:00 PM and tapers off to 0 after 6:00 PM. This hourly trend underscores the importance of sun protection during the midday hours when the 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 | 11 | extreme | 10 min |
| 13:00 | 9 | very high | 15 min |
| 14:00 | 6 | high | 25 min |
| 15:00 | 3 | moderate | 30 min |
| 16:00 | 1 | low | 45 min |
| 17:00 | 1 | low | 45 min |
| 18:00 | 0 | low | 45 min |
| 19:00 | 0 | low | 45 min |
The UV Index data reveals significant seasonal variations, with extreme exposure levels predominantly influencing the first nine months of the year. Notably, January to April show high UV values ranging from 12 to 15, marking these as critical months with a burn time of only 10 minutes. Although June offers a slight respite with a very high UV Index of 10 (burn time increases to 15 minutes), the threat escalates again in July and August, returning to extreme levels. September continues this trend with a UV Index of 14, dropping slightly in October through December, but maintaining a consistently extreme level of 13 throughout the winter months. Visitors and residents should remain vigilant, especially from January to September, ensuring the use of adequate sun protection measures, like sunscreen, protective clothing, and seeking shade, particularly during peak UV hours.
UV Risk Categories
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Surabaya | 13 | 15 | 14 | 12 | 12 | 10 | 11 | 12 | 14 | 13 | 13 | 13 |
| Bekasi UVI | 14 | 16 | 16 | 14 | 11 | 10 | 10 | 11 | 13 | 15 | 14 | 13 |
| Jakarta UVI | 14 | 16 | 16 | 14 | 11 | 10 | 10 | 11 | 13 | 15 | 14 | 13 |
| Medan UVI | 13 | 15 | 15 | 15 | 14 | 12 | 12 | 13 | 14 | 14 | 13 | 12 |
| Bandung UVI | 15 | 16 | 16 | 15 | 12 | 11 | 11 | 12 | 14 | 15 | 15 | 14 |