Last updated: August 1, 2025
Understanding the UV Index is crucial for residents and visitors in Sumurgung, Indonesia, where the warm, tropical climate results in high levels of UV radiation, especially during midday hours. Being aware of UV levels is essential for preventing sunburns and maintaining healthy skin, as prolonged exposure can lead to serious health issues. With maximum UV Index readings soaring to 11 around noon, it's vital to know when to seek shade and protect your skin from potential harm. Whether exploring the beautiful beaches or enjoying outdoor activities, staying informed about the UV Index will help you enjoy the sun safely in this idyllic locale.
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 | 2 | low | 45 min |
| 08:00 | 4 | moderate | 30 min |
| 09:00 | 8 | very high | 15 min |
| 10:00 | 11 | extreme | 10 min |
| 11:00 | 13 | extreme | 10 min |
| 12:00 | 13 | extreme | 10 min |
| 13:00 | 10 | very high | 15 min |
| 14:00 | 7 | high | 25 min |
| 15:00 | 4 | 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 exhibits significant seasonal variation, peaking during the early months of the year with values reaching up to 16 in February and remaining extremely high through March and April. Notably, the high-risk months for UV exposure are from January to April, as well as July through September, when the UV Index often hits extreme levels, leading to a burn time of just 10 minutes for unprotected skin. As temperatures rise into the summer months, the index drops slightly, with June showing a very high level of 10, and a burn time of 15 minutes. Visitors and residents should take precautions by applying sunscreen, wearing protective clothing, and seeking shade during peak hours, especially in the high-risk months to minimize the risk of skin damage.
UV Risk Categories
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Surabaya UVI | 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 |
| Sumurgung | 14 | 16 | 15 | 13 | 13 | 10 | 11 | 13 | 14 | 14 | 14 | 14 |
| 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 |