Air quality in Siheung-si, South Korea today

Mr. Duck’s Air Quality Score

Unhealthy for sensitive groups for Siheung-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 today in Siheung‑si is classified as USG. The primary pollutant identified is PM2.5 (fine particles). Measurements show a PM2.5 reference value of 38.0 and a PM10 reference value of 56.0, based on 42 valid observations collected via OpenAQ.

These figures 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 Siheung‑si air‑quality feed includes six measured pollutants – carbon monoxide (CO), nitrogen dioxide (NO₂), ozone (O₃), particulate matter 10 µm or smaller (PM10), fine particulate matter 2.5 µm or smaller (PM2.5) and sulfur dioxide (SO₂). Data come from seven monitoring stations, each providing a recent snapshot that was last refreshed on 2026‑02‑10 18:00 UTC; every pollutant record falls within the “updated within 7 days” freshness bucket.

Across the city the observed values show a fairly tight spread for most gases. CO ranges from a low of 0.37 ppm to a high of 0.59 ppm, with a median near 0.50 ppm; NO₂ varies between 0.0163 ppm and 0.041 ppm, centering around 0.029 ppm. Ozone is the most variable in absolute terms, recorded as low as 0.0012 ppm and reaching up to 0.0282 ppm, while its median sits at 0.00435 ppm. The particulate measurements are higher in magnitude: PM10 values sit between 33 µg/m³ and 62 µg/m³ (median 49 µg/m³) and PM2.5 spans 11 µg/m³ to 43 µg/m³ (median 35.5 µg/m³). Sulfur dioxide is the least variable, ranging from 0.0024 ppm to 0.0037 ppm with a median of about 0.0033 ppm.

Because all seven stations reported within the same recent window, the dataset offers city‑wide coverage that reflects current conditions rather than historic averages. However, the number of rows per pollutant is limited to ten recent samples per station, so while the snapshot is fresh, it does not capture longer‑term fluctuations. Users should keep in mind that air quality can differ across neighborhoods and over time, and the values presented represent the latest available measurements from this network.

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 Siheung‑si is based on 42 valid measurements and was refreshed Updated within 3 days, with the most recent update recorded at 2026‑02‑10T18:00:00+00:00. This snapshot reflects conditions measured across the city’s monitoring network but air quality can vary by location and time within Siheung‑si, so values may differ from what you experience at a specific spot or moment.

OpenAQ station rows