Air quality in Koga, Japan today

Mr. Duck’s Air Quality Score

Moderate air today for Koga, Japan

⚠️ 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 Koga is currently rated as Moderate. The main pollutant identified is PM2.5 (fine particles). Measurements show a PM2.5 concentration of 10.0 µg/m³, based on seven valid observations reported through OpenAQ.

Data indicate that particulate matter levels are at the reference value for PM2.5, while no PM10 reference is available. This assessment reflects the latest set of readings without additional context or forecasting. 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 Koga dataset includes six measured pollutants – carbon monoxide (CO), nitrogen oxide (NO), nitrogen dioxide (NO₂), total nitrogen oxides (NOX), fine particulate matter (PM2.5) and sulfur dioxide (SO₂). Data come from 11 individual rows collected at two monitoring stations, with each pollutant recorded by either one or two sensors. All values were last updated on 2026-02-10 22:00 UTC, so the information is current within the past three days for every pollutant.

Carbon monoxide shows a modest spread, ranging from 0.0 to 0.3 ppm and a median of 0.15 ppm across its two sensors. Nitrogen oxide values are low but variable, with a minimum of 0.002 ppm, a maximum of 0.041 ppm and a median near 0.022 ppm. NO₂ concentrations sit between 0.004 and 0.017 ppm (median 0.0105 ppm), while the combined NOX metric ranges from 0.019 to 0.045 ppm (median 0.032 ppm). PM2.5 measurements span 2.0 to 10.0 µg/m³, with a median of 6.0 µg/m³ and most readings clustered between the 10th percentile (2.8 µg/m³) and the 90th percentile (9.2 µg/m³). Sulfur dioxide is reported by only one sensor, consistently at 0.001 ppm.

The dataset provides fairly recent coverage but shows uneven sensor distribution: SO₂ has a single observation point, whereas CO, NO, NO₂, NOX and PM2.5 each have two. This means spatial variation for sulfur dioxide cannot be assessed as thoroughly as for the other pollutants. Overall, the data capture a snapshot of air quality across Koga with recent timestamps, yet the limited number of stations implies that conditions may differ in parts of the city not directly monitored.

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 reflects seven valid measurements and is marked as Updated within 3 days, with the latest values recorded at 2026‑02‑10T22:00:00+00:00. While these figures provide a current snapshot of air quality in Koga, conditions can differ across neighborhoods and change throughout the day, so local variations may not be captured by this summary.

OpenAQ station rows