10 Most Polluted Regions in Indonesia This Morning (9/12)

Air quality in North Sumatra this morning is the worst in Indonesia. Based on the Air Quality Index (AQI) page of the Ministry of Environment and Forestry (KLHK) on Tuesday (9/12/2025) at 08.00 AM WIB, it was revealed that the air quality index in North Sumatra was 100.

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

AQI calculation is based on the measurement results of seven air pollutant parameters, namely PM10, PM2.5, NO2, SO2, CO, O3, and HC. The measurement of air pollutant parameters is distributed across 72 stations in various regions.

(Read: A 4.1 M Earthquake Shakes 2 Km East of Cartago, Costa Rica)

Based on Minister of Environment and Forestry Regulation No. 14 of 2020 concerning the Air Quality Index, an AQI in the range of 0-50 indicates good air quality, 51-100 means moderate air quality, and 101-200 means unhealthy air quality which 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 prompt action.

Below North Sumatra, Riau ranks second worst in Indonesia with an air quality index of 99. Then, in third place is Banten with an air quality index of 95.

This means that no region has hazardous air quality.

Here is the list of the 10 provinces with the worst air quality index in Indonesia on Tuesday, December 9, 2025, at 08.00 AM WIB.

1. North Sumatra: 100

2. Riau: 99

3. Banten: 95

4. Jambi: 94

5. West Java: 87

6. West Sumatra: 86

7. South Sumatra: 85

8. Central Kalimantan: 82

9. West Papua: 76

10. East Kalimantan: 75

(Read: A 4.1 M Earthquake Shakes 2 Km East of Cartago, Costa Rica)