10 Most Polluted Regions in Indonesia This Morning (21/1)

Air quality in Riau this morning is the worst in Indonesia. Based on the Air Pollution Standard Index (ISPU) page of the Ministry of Environment and Forestry (KLHK) on Wednesday (21/1/2026) at 08:00 AM WIB, the air quality index in Riau was 100.

According to the KLHK Directorate of Air Pollution Control, ISPU is a unitless number used to describe ambient air quality conditions at a certain 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: PM10, PM2.5, NO2, SO2, CO, O3, and HC. Measurements of these air pollutant parameters are spread across 72 stations in various regions.

(Read: West Kalimantan Produced the Most CO2 Emissions from Forest and Land Fires Until July 2023)

Based on KLHK Regulation No. 14 of 2020 concerning the Air Pollution Standard Index, an ISPU range of 0-50 indicates good air quality, 51-100 indicates 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 prompt handling.

Below Riau, Banten occupies the second-worst position in Indonesia with an air quality index of 95. Then, in third place is Central Kalimantan with an air quality index of 90.

This means that no region has hazardous air quality.

Here is a list of the 10 provinces with the worst air quality index in Indonesia on Wednesday, January 21, 2026, at 08:00 AM WIB.

1. Riau: 100

2. Banten: 95

3. Central Kalimantan: 90

4. Jambi: 88

5. West Sumatra: 87

6. Aceh: 84

7. West Java: 83

8. South Sumatra: 82

9. North Sumatra: 77

10. West Kalimantan: 76

(Read: West Kalimantan Produced the Most CO2 Emissions from Forest and Land Fires Until July 2023)