Riau is the Most Polluted in Indonesia Tonight (April 18)

Riau has the worst air quality in Indonesia tonight. Based on the Air Pollution Standard Index (ISPU) page of the Ministry of Environment and Forestry (KLHK) on Saturday (April 18, 2026) at 6:00 PM WIB, it was revealed that the air quality index in Riau is 97.

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

ISPU calculations are based on measurements of seven air pollutant parameters: PM10, PM2.5, NO2, SO2, CO, O3, and HC. Air pollutant parameter measurements are spread across 72 stations in various regions.

(Read: Number of Earthquake Disaster Victims in Indonesia in 2020-2024)

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

Next, very unhealthy air quality in the 201-300 range can increase health risks for sensitive groups. Meanwhile, hazardous air quality in the range above 300 can seriously harm health and requires immediate handling.

Below Riau, South Sumatra ranks second worst in Indonesia with an air quality index of 93. Then, Jambi ranks third with an air quality index of 91.

This means that no region has hazardous air quality.

Here is the list of 10 provinces with the worst air quality index in Indonesia on Saturday, April 18, 2026 at 6:00 PM WIB.

1. Riau: 97

2. South Sumatra: 93

3. Jambi: 91

4. Aceh: 89

5. West Sumatra: 87

6. West Java: 83

7. South Sulawesi: 82

8. Central Kalimantan: 80

9. East Java: 71

10. East Kalimantan: 68

(Read: Number of Earthquake Disaster Victims in Indonesia in 2020-2024)