Air quality in Yesan-gun, South Korea today

Mr. Duck’s Air Quality Score

Moderate air today for Yesan-gun, 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

Today the air quality in Yesan-gun is classified as Moderate. The primary pollutant identified is PM2.5, based on twelve valid measurements reported through OpenAQ. This Moderate category reflects that the observed concentrations are above the lowest level but do not reach higher tiers used in public reporting. All figures are compiled from the OpenAQ platform, which gathers data from local monitoring stations.

According to the latest data, the PM2.5 concentration is 24.0 µg/m³ and the PM10 concentration is 28.0 µg/m³. Both values correspond to the reference values supplied for this assessment. The measurements are presented without additional interpretation and are displayed via OpenAQ. 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 Yesan‑gun dataset pulls in six measured 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) – from three monitoring stations. In total there are 24 observation rows, of which 18 were recorded within the most recent 30 days and six are older than that. The newest timestamp for every pollutant is the same: 2026‑02‑10 18:00 UTC, so the data are up to date to within a few weeks but there are no readings from today or the past week.

Across the six pollutants the typical values are modest. The median CO concentration is 0.505 ppm, with a low of 0.26 ppm and a high reported as 9 999 ppm – the extreme upper bound appears to be a placeholder rather than a realistic measurement. NO₂ shows a median of 0.0081 ppm, ranging from 0.0072 ppm up to the same 9 999 ppm placeholder; O₃ median is 0.014 ppm, with a minimum of 0.004 ppm. For the particulate matter metrics, the median PM10 is 38 µg/m³ (minimum 26 µg/m³) and the median PM2.5 is 24 µg/m³ (minimum 20 µg/m³), again with the 9 999 µg/m³ ceiling indicating possible data‑quality flags. SO₂ median sits at 0.00405 ppm, between 0.0027 ppm and the 9 999 ppm ceiling. The 10th‑percentile values cluster close to the minima (e.g., CO 0.308 ppm, NO₂ 0.00723 ppm), while the 90th‑percentile values jump dramatically toward the placeholder maximums, showing a wide spread between typical and extreme reported figures. Because the observations are limited to three sites and many rows are older than a month, the snapshot may not capture short‑term variations across the wider county, and conditions can differ by location and time.

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

This dataset includes 12 valid measurements and has been updated within 30 days. The latest update was recorded on 2026-02-10 at 18:00 UTC. Measurements are taken from certified monitoring stations across Yesan‑gun and reflect conditions at the time of sampling. Please note that air quality can vary by location and time within the city. Data are provided for informational purposes only.

OpenAQ station rows