Air quality in Hwaseong-si, South Korea today

Mr. Duck’s Air Quality Score

Unhealthy for sensitive groups for Hwaseong-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 Hwaseong-si is classified as USG. The primary pollutant identified is PM2.5 (fine particles). Data are based on 36 valid measurements reported through OpenAQ.

Current observations show a PM2.5 concentration of 43.0 µg/m³ and a PM10 concentration of 50.0 µg/m³. These values reflect the latest available readings for the city. Measurements were recorded during the reporting period and aggregated for the current assessment. OpenAQ compiles data from multiple monitoring stations to provide a consolidated view. The set of 36 valid observations meets the criteria for a reliable snapshot of ambient conditions. The reported values correspond to the most recent sampling interval as of 2026-02-23 00:00 UTC. This page is informational; for 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 Hwaseong‑si brings together recent measurements of six key air‑quality pollutants—carbon monoxide (CO), nitrogen dioxide (NO₂), ozone (O₃), particulate matter 10 µm (PM10), particulate matter 2.5 µm (PM2.5) and sulfur dioxide (SO₂). Data are drawn from seven monitoring stations and compiled into 54 individual rows, each reflecting a snapshot taken at the same moment: 2026‑02‑10 18:00 UTC. Because every pollutant’s last‑updated timestamp falls on that date, the information is fresh, having been recorded within the past 30 days.

Across the pollutants the observed values show a modest central tendency but a very wide reported spread. The median CO concentration is 0.38 ppm, with the lowest reading at 0.27 ppm and a maximum recorded as 9 999 ppm, which pushes the 90th‑percentile to an extreme 2 000.24 ppm. NO₂ and O₃ follow a similar pattern: medians of 0.0156 ppm and 0.0204 ppm, minima of 0.0053 ppm and 0.0032 ppm, and maxima again capped at 9 999 ppm, inflating their upper‑percentile values. Particulate matter shows a comparable median (PM10 45 µg/m³, PM2.5 36 µg/m³) and a low end (PM10 33 µg/m³, PM2.5 19 µg/m³), yet the same 9 999 µg/m³ ceiling creates a pronounced disparity between typical and extreme reported figures. SO₂ is the most tightly clustered, with a median of 0.004 ppm, a minimum of 0.0034 ppm and the identical high ceiling that drives its 90th‑percentile upward.

The most recent specific readings, all taken at the 동탄 site, are 0.42 ppm CO, 0.0203 ppm NO₂, 0.0141 ppm O₃, 50.0 µg/m³ PM10, 43.0 µg/m³ PM2.5 and 0.004 ppm SO₂. While the timestamps are uniformly current, the presence of placeholder maximum values means the extreme ends of the reported ranges should be interpreted with caution, and actual conditions may vary across different neighborhoods and times within the city.

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 Hwaseong‑si includes 36 valid measurements and is Updated within 30 days. The most recent data were recorded on 2026‑02‑10 at 18:00 UTC. This snapshot reflects conditions at the time of collection, but air quality can vary by location and time within the city. Users should consider potential short‑term fluctuations when interpreting the values.

OpenAQ station rows