West Kalimantan's Air Quality on Saturday Night (31/1) is the Worst in Indonesia

Air quality in West Kalimantan tonight is the worst in Indonesia. Based on the Air Pollution Standard Index (ISPU) page of the Ministry of Environment and Forestry (KLHK) on Saturday (31/1/2026) at 6:00 PM WIB, it was revealed that the air quality index in West Kalimantan was 98.

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

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

(Read: Volcanic Eruption Trends in Recent Years)

Based on Ministry of Environment and Forestry Regulation No. 14 of 2020 concerning the Air Pollution Standard Index, an ISPU 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.

Next, 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 West Kalimantan, Banten ranks second worst in Indonesia with an air quality index of 95. Then, in third place is Riau with an air quality index of 94.

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 Saturday, January 31, 2026, at 6:00 PM WIB.

1. West Kalimantan: 98

2. Banten: 95

3. Riau: 94

4. South Sumatra: 91

5. Jambi: 89

6. South Kalimantan: 86

7. West Java: 84

8. Aceh: 83

9. North Sumatra: 79

10. Central Kalimantan: 74

(Read: Volcanic Eruption Trends in Recent Years)