Riau Islands Most Polluted in Indonesia Tonight (9/11)

Air quality in Riau Islands tonight is the worst in Indonesia. Based on the Air Pollution Standard Index (ISPU) page of the Ministry of Environment and Forestry (KLHK) on Sunday (9/11/2025) at 6:00 PM WIB, it was revealed that the air quality index in Riau Islands was 95.

According to the KLHK Directorate of Air Pollution Control, ISPU is a unitless number used to describe ambient air quality conditions at a specific location, based on its impact on human health, aesthetic value, and other living things.

ISPU calculation is based on the measurement results of seven air pollutant parameters, namely PM10, PM2.5, NO2, SO2, CO, O3, and HC. Air pollutant parameter measurements are spread across 72 stations in various regions.

(Read: There are Still 381 High-Risk Forest and Land Fire Hotspots in Indonesia in Early 2023)

Based on Ministry of Environment and Forestry Regulation No. 14 of 2020 concerning the Air Pollution Standard Index, ISPU in the range of 0-50 indicates good air quality, 51-100 means moderate air quality, and 101-200 indicates unhealthy air quality that is detrimental to humans, animals, and plants.

Furthermore, very unhealthy air quality in the range of 201-300 can increase health risks for sensitive groups. Meanwhile, hazardous air quality in the range of more than 300 can seriously harm health and requires quick action.

Below Riau Islands, West Sumatra ranks second worst in Indonesia with an air quality index of 87. Then, in third place is South Sumatra with an air quality index of 85.

This means no region has hazardous air quality.

Here is the list of the 10 provinces with the worst air quality index in Indonesia on Sunday, November 9, 2025, at 6:00 PM WIB.

1. Riau Islands: 95

2. West Sumatra: 87

3. South Sumatra: 85

4. West Java: 84

5. North Sumatra: 82

6. Riau: 80

7. East Java: 76

8. South Sulawesi: 75

9. Central Java: 69

10. Central Kalimantan: 68

(Read: There are Still 381 High-Risk Forest and Land Fire Hotspots in Indonesia in Early 2023)