Air quality in Kumamoto, Japan today

Mr. Duck’s Air Quality Score

Unhealthy for sensitive groups for Kumamoto, 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 Kumamoto is classified as USG today. The primary pollutant identified is PM2.5, with a measured concentration of 40.0 µg/m³ based on 36 valid observations reported through OpenAQ.

These data reflect the current state of fine particulate matter without additional context or interpretation. 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 dataset for Kumamoto 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). Across the city there are 36 individual data rows drawn from eight monitoring stations, but coverage is uneven: CO is reported from a single sensor, while PM2.5, NO, NO₂, NOX and SO₂ each have between six and seven recent readings.

All of the latest observations were recorded on 2026-02-10 at 22:00 UTC, so the freshest data are less than three days old. For PM2.5 the values range from a low of 4 µg/m³ to a high of 40 µg/m³ with a median of 9 µg/m³; the 10th and 90th percentiles sit at 4 µg/m³ and roughly 19.7 µg/m³, indicating that most recent measurements cluster around single‑digit concentrations but occasional spikes are present. Nitrogen oxides show similarly tight spreads: NO varies between 0 and 0.01 ppm (median 0.001 ppm), NO₂ runs from 0.007 to 0.017 ppm (median 0.011 ppm) and NOX spans 0.008 to 0.027 ppm (median 0.012 ppm). Sulfur dioxide is consistently low, recorded between 0 and 0.001 ppm with a median of 0.0005 ppm. The lone CO reading sits at 0.2 ppm.

Because some pollutants are captured at only a handful of sites while others have broader station representation, the snapshot reflects a mix of well‑sampled and sparsely sampled conditions. Users should keep in mind that air quality can differ across neighborhoods and times of day, and the current dataset provides a recent but limited view of Kumamoto’s atmospheric composition.

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 Kumamoto includes 36 valid measurements and is refreshed regularly, having been Updated within 3 days; the latest data were recorded on 2026‑02‑10 at 22:00 UTC. While this snapshot reflects current conditions across the monitoring network, air quality can differ by specific location and time of day within the city, so individual experiences may vary.

OpenAQ station rows