Riau's Air Quality on Monday Night (1/12) is the Worst in Indonesia

Riau's air quality tonight is the worst in Indonesia. Based on the Air Pollution Standard Index (ISPU) page of the Ministry of Environment and Forestry (KLHK) on Monday (1/12/2025) at 6:00 PM WIB, Riau's air quality index was 97.

According to the KLHK Directorate of Air Pollution Control, ISPU is a dimensionless 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 calculations are based on measurements 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: Indonesia's Flood Disaster Trend Over a Decade, Starting to Decline Since 2021)

Based on KLHK 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 handling.

Below Riau, Kep. Riau ranks second worst in Indonesia with an air quality index of 95. Then, in third place is North Sumatra 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 Monday, December 1, 2025 at 6:00 PM WIB.

1. Riau: 97

2. Kep. Riau: 95

3. North Sumatra: 90

4. Central Java: 89

5. Jambi: 88

6. West Sumatra: 87

7. East Java: 86

8. South Sumatra: 82

9. DKI Jakarta: 76

10. North Sulawesi: 72

(Read: Indonesia's Flood Disaster Trend Over a Decade, Starting to Decline Since 2021)