Air quality in Kosai, Japan today

Mr. Duck’s Air Quality Score

Moderate air today for Kosai, 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 Kosai is currently classified as Moderate. The main pollutant identified is PM2.5, with a measured concentration of 17.0 µg/m³ based on five valid observations reported through OpenAQ.

These values reflect the present monitoring snapshot 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 dataset for Kosai includes five measured pollutants – nitrogen monoxide (NO), nitrogen dioxide (NO2), combined nitrogen oxides (NOX), fine particulate matter (PM2.5) and sulfur dioxide (SO2). All observations come from a single monitoring site, identified as 湖西市吉美３２６８, so the city’s air‑quality picture is based on one location rather than a network of stations.

Each pollutant has a single recorded value because the minimum, median and maximum are identical. NO registers at 0.001 ppm, NO2 at 0.012 ppm, NOX at 0.013 ppm, PM2.5 at 17.0 µg/m³ and SO2 is measured as 0.0 ppm. The lack of variation means there is no observed spread or percentile range for any constituent; the data represent a snapshot rather than a distribution over time.

All five readings share the same last‑updated timestamp of 2026-02-10 22:00 UTC, which falls within the “updated within 3 days” freshness category. Because every pollutant was recorded at the same moment, there is no evidence of staggered or older measurements in this set. Consequently, while the information is current, it reflects conditions only at one point and one place; air quality can differ across other neighborhoods or later times in Kosai.

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 current air‑quality values for Kosai are based on five valid measurements and were refreshed recently, having been updated within three days (last update: 2026‑02‑10 22:00 UTC). These figures represent a snapshot from the monitoring network and may not capture short‑term fluctuations. Air quality can vary by location and time within the city, so conditions at specific sites or moments may differ from those shown here.

OpenAQ station rows