Last updated: July 2, 2025
Understanding the UV Index is crucial for residents and visitors of Mergayu, Indonesia, where the tropical climate brings intense sun exposure. With UV levels peaking sharply between 10 AM and 2 PM, reaching a high of 11, awareness of these levels is vital for preventing sunburn and protecting skin health. In this sun-soaked region, knowing when to seek shade or apply sunscreen can make all the difference in enjoying the outdoors while minimizing risk. Stay informed and ensure your time under the Indonesian sun is safe and enjoyable!
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 |
Throughout the year, UV exposure remains particularly high, with January through April experiencing an extreme UV Index consistently at 15. As spring gives way to summer, May sees a slight decrease at 12, followed by a very high index of 10 in June. From July to September, the UV Index fluctuates between 11 and 15, staying in the extreme category during these months. October to December returns to 15, reinforcing that the risk remains high, even in winter. The high-risk months for UV exposure are January, February, March, July, August, September, October, November, and December, where outdoor enthusiasts and residents should take precautions. It is essential for visitors and residents alike to ensure adequate sun protection, such as wearing sunscreen, protective clothing, and seeking shade, especially during peak sun hours, to mitigate the risk of harmful UV exposure.
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 |
| 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 |
| Mergayu | 15 | 15 | 15 | 14 | 12 | 10 | 11 | 13 | 15 | 15 | 15 | 15 |