What is the air quality trend in Ansan-si?

Over the past 8 days, Ansan-si had an average AQI of 40 based on station measurements. The worst day was 2026-10-16 with AQI 50.

How is Ansan-si air quality measured?

Air quality in Ansan-si is measured by ground-level monitoring stations that report PM2.5 and PM10 concentrations hourly. CERNS.IO aggregates readings from nearby stations and converts PM2.5 to the US EPA Air Quality Index (AQI) scale.

Air Quality History for Ansan-si, South Korea

Name: Ansan-si Air Quality History
Creator: CERNS.IO
License: https://creativecommons.org/licenses/by/4.0/

Historical PM2.5 and AQI trend from monitoring stations near Ansan-si, South Korea.

Current AQI
Good Station

48 Hours 7 Days 14 Days 20 Days

CSV JSON

Air Quality Index Station

165h

PM2.5 Station

165h · 33 stations

Temperature GFS model

28pt

Precipitation GFS model

mm/day

Daily Summary Station

Date	AQI	Range	PM2.5 avg	Hours	Stations
2026-10-21	46	40–51	11.0 µg/m³	4h	63
2026-10-20	39	22–50	9.3 µg/m³	24h	78
2026-10-19	37	21–48	8.8 µg/m³	24h	78
2026-10-18	35	20–55	8.5 µg/m³	24h	80
2026-10-17	44	26–62	11.0 µg/m³	24h	74
2026-10-16	50	21–66	13.1 µg/m³	24h	78
2026-10-15	40	25–52	9.5 µg/m³	24h	76
2026-10-14	32	20–41	7.6 µg/m³	17h	69

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