Air quality in Cheongju-si, South Korea today

Mr. Duck’s Air Quality Score

Unhealthy air today for Cheongju-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 Cheongju‑si is currently classified as Unhealthy. The primary pollutant identified is PM2.5 (fine particles). Measurements show a PM2.5 value of 65.0 and a PM10 value of 65.0, based on 53 valid observations collected via OpenAQ.

These figures reflect the present conditions without implying any trend or cause. 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

Cheongju‑si’s air‑quality feed draws from nine monitoring stations that together contribute 66 recent observations across six key 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). All of the latest readings were recorded at 2026‑02‑10 18:00 UTC, so the data are fresh enough to reflect conditions within the past week.

The CO values span from a low of 0.37 ppm to a high of 0.88 ppm, with a median around 0.45 ppm; the most extreme recent measurement (0.77 ppm) was observed at the 가덕면 site. NO₂ concentrations range between 0.0085 ppm and 0.0214 ppm, centering near 0.016 ppm, while the highest reported level (0.0136 ppm) also comes from 가덕면. Ozone shows a broader spread, from 0.0062 ppm up to 0.0392 ppm, with a median of 0.0207 ppm and the lowest recent reading (0.0066 ppm) recorded at the same location.

Particulate matter exhibits the widest variability. PM₁₀ values fall between 28 µg/m³ and 65 µg/m³, with a typical level near 43 µg/m³; the maximum recent value (65 µg/m³) was measured at 가덕면. PM₂.₅ shares a similar pattern, ranging from 26 µg/m³ to an outlier of 9 999 µg/m³, though the 90th‑percentile caps at 65 µg/m³ and the median sits at 35 µg/m³, again with the highest recent reading (65 µg/m³) from 가덕면. SO₂ is the least variable, staying between 0.0017 ppm and 0.0037 ppm, with a median of 0.0022 ppm and the latest reported value (0.0022 ppm) also taken at 가덕면.

Overall, the dataset provides a complete set of six pollutants across all stations, but the concentration figures are dominated by readings from the 가덕면 monitor, indicating that spatial coverage may be uneven. While the timestamps are uniformly recent, the limited number of stations means conditions can differ in other parts of Cheongju‑si at any given moment.

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 Cheongju‑si includes 53 valid measurements and is updated within 3 days, with the most recent values recorded at 2026‑02‑10T18:00:00+00:00. While these figures provide a current overview of citywide air quality, conditions can differ across neighborhoods and change throughout the day, so this snapshot may not reflect localized or moment‑to‑moment variations.

OpenAQ station rows