Air quality in Ansan, South Korea today

Mr. Duck’s Air Quality Score

Unhealthy for sensitive groups for Ansan, South Korea

⚠️ This website is currently under active development. Some data may be incomplete or temporarily inaccurate. For health-critical decisions, please verify information through official government or environmental sources.

Categories follow US EPA AQI breakpoints for PM (estimate from latest valid measurements; this project does not compute EPA NowCast/24-hour AQI yet).

This friendly indicator summarizes the latest city readings. For health guidance, please see: EPA AirNow or WHO.

Air quality today

The air quality today in Ansan is classified as USG. The primary pollutant identified is PM2.5 (fine particles). Measurements show a PM2.5 reference value of 45.0 and a PM10 reference value of 59.0, based on 47 valid observations.

These figures are presented through OpenAQ data for the city. This page is informational; for health guidance, use official sources such as EPA AirNow or WHO.

Latest sensor values

PM categories follow US EPA AQI breakpoints, shown here as an estimate derived from the latest valid measurements (this project does not compute EPA NowCast/24-hour AQI yet).

What the data includes

The dataset for Ansan pulls hourly readings from nine monitoring stations, giving a total of 72 recent records. Across those records, 48 rows have been updated within the past seven days while another 24 are older than that window; none are from today or the last three days. All six common air‑quality pollutants are represented: carbon monoxide (CO), nitrogen dioxide (NO₂), ozone (O₃), particulate matter ≤10 µm (PM10), particulate matter ≤2.5 µm (PM2.5) and sulfur dioxide (SO₂). For each pollutant the most recent value comes from the 부곡동1 station, recorded at 2026‑02‑10 18:00 UTC.

The measurements show a fairly wide spread. CO values range from a low of 0.20 ppm to a high capped at 9 999 ppm, with the median sitting at 0.46 ppm; the latest reading is 0.58 ppm. NO₂ spans 0.005‑9 999 ppm, median 0.0228 ppm and recent value 0.0352 ppm. O₃ ranges from 0.0011‑9 999 ppm, median 0.01165 ppm, latest 0.0011 ppm. PM10 concentrations vary between 17 µg/m³ and the same upper cap, with a median of 41.5 µg/m³; the newest figure is 43.0 µg/m³. PM2.5 shows a minimum of 9 µg/m³, median 33 µg/m³, and the most recent reading of 44.0 µg/m³. SO₂ values extend from 0.0015‑9 999 ppm, median 0.00255 ppm, latest 0.0023 ppm.

Because a quarter of the rows are older than seven days, the snapshot does not capture every short‑term fluctuation across the city. The data set provides a decent baseline for typical conditions—median values give an idea of central tendency—but users should keep in mind that local air quality can differ by neighborhood and time, especially when recent observations are limited.

Learn more about sources and filtering: About the data.

Trusted references: WHO (Air pollution) · US EPA AirNow · European Environment Agency (Air)

Latest sensor values (bars)

PM categories follow US EPA AQI breakpoints, shown here as an estimate derived from the latest valid measurements (this project does not compute EPA NowCast/24-hour AQI yet).

Data notes

The dataset for Ansan includes 47 valid measurements and is refreshed Updated within 3 days, with the most recent data recorded at 2026‑02‑10T18:00:00+00:00. This snapshot reflects conditions captured across the monitoring network at that time; however, air quality can differ by specific location and moment within the city, so values may not represent every street or hour.

OpenAQ station rows