Last updated: August 1, 2025
Awareness of the UV Index is vital for residents of Gresik, Indonesia, where the tropical climate can lead to significant sun exposure risks. Understanding UV levels is crucial for preventing sunburn and protecting skin health, especially given the area's high UV readings, peaking at 11 between 11:00 and 12:00. With typical sunshine coupled with warm temperatures, residents should remain vigilant about UV exposure throughout the day, particularly during peak hours. By staying informed and taking appropriate precautions, you can enjoy the beautiful weather in Gresik while keeping your skin safe from harmful UV rays.
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 | 12 | extreme | 10 min |
| 12:00 | 12 | extreme | 10 min |
| 13:00 | 10 | very high | 15 min |
| 14:00 | 7 | 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 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Gresik | 13 | 15 | 14 | 12 | 12 | 10 | 11 | 12 | 14 | 13 | 13 | 13 |
| 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 |