10 Most Polluted Regions in Indonesia Tonight (25/2)

North Sumatra 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 Wednesday (February 25, 2026) at 18:00 WIB, it was revealed that the air quality index in North Sumatra is 102.

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: Nearly 5,000 Natural Disasters in Indonesia Throughout 2023, Forest and Land Fires Dominate)

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

After North Sumatra, Banten ranks second with the worst air quality in Indonesia with an index of 95. Then, Riau ranks third with an air quality index of 93.

This means that no region has hazardous air quality.

Here is the list of 10 provinces with the worst air quality indices in Indonesia on Wednesday, February 25, 2026 at 18:00 WIB.

1. North Sumatra: 102

2. Banten: 95

3. Riau: 93

4. West Java: 90

5. North Sumatra: 89

6. Aceh: 88

7. West Sumatra: 87

8. South Kalimantan: 76

9. Lampung: 74

10. South Sulawesi: 66

(Read: Nearly 5,000 Natural Disasters in Indonesia Throughout 2023, Forest and Land Fires Dominate)