Air quality in Osan-si, South Korea today

Mr. Duck’s Air Quality Score

Unhealthy for sensitive groups for Osan-si, 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 in Osan‑si is classified as USG today. The primary pollutant identified is PM2.5, with a measured concentration of 36.0 µg/m³. In addition, the level for larger particles (PM10) is recorded at 47.0 µg/m³ based on twelve valid observations.

Data are shown via OpenAQ and reflect the current monitoring results 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 Osan‑si contains hourly observations from three monitoring stations, each providing a full set of six common air‑quality gases and particles: carbon monoxide (CO), nitrogen dioxide (NO₂, written as NO2), ozone (O₃, written as O3), particulate matter 10 µm or smaller (PM10), particulate matter 2.5 µm or smaller (PM2.5, written as PM25), and sulfur dioxide (SO₂). All six pollutants are represented in every station row, giving a uniform coverage across the city.

The most recent measurements were recorded on 2026‑02‑10 at 18:00 UTC, so the freshest data are just a few days old for each pollutant. Median values show that CO typically sits around 0.43 ppm, NO₂ near 0.0233 ppm, O₃ about 0.0046 ppm, PM10 around 45 µg/m³, PM2.5 roughly 35 µg/m³, and SO₂ close to 0.0024 ppm. The observed ranges are relatively tight: CO varies from a low of 0.31 ppm to a high of 0.48 ppm; NO₂ spans 0.0201–0.0279 ppm; O₃ runs between 0.003 and 0.0232 ppm; PM10 fluctuates from 28 µg/m³ up to 47 µg/m³; PM2.5 moves between 19 µg/m³ and 36 µg/m³; and SO₂ is recorded between 0.0024 ppm and 0.0029 ppm. The 10th‑percentile values are close to the minima for most pollutants, while the 90th‑percentile values approach the maxima, indicating that extreme readings are uncommon in this short snapshot.

Because all three stations report the same set of pollutants, there is no missing data for any of the six measured species, but the limited number of stations means spatial variation within Osan‑si cannot be captured in detail. The dataset’s freshness—updates within the last week—provides a current picture, yet conditions can still differ across neighborhoods and over time beyond what these three points show.

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 data shown for Osan‑si is based on 12 valid measurements and was refreshed within the past three days, with the latest update recorded at 2026‑02‑10T18:00:00+00:00. This snapshot reflects conditions at the time of collection; air quality can differ across neighborhoods and change throughout the day, so values may not represent every location or moment in the city.

OpenAQ station rows