Air quality in Hayama, Japan today

Mr. Duck’s Air Quality Score

Good air today for Hayama, 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 Hayama is classified as Good today. The primary pollutant identified is PM2.5, with a measured concentration of 2.24 µg/m³ based on five valid observations reported through OpenAQ.

Overall conditions are favorable according to the available data. 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

Hayama’s public air‑quality feed draws from a single monitoring location – Kamiyamaguchi – and therefore contains one row of data for each pollutant. The dataset supplies five measured variables: PM1, PM2.5, relative humidity, temperature and the particle count UM003. All values were last refreshed on 2026-02-10 23:00 UTC, so the most recent observations are just a few days old.

The numbers show virtually no spread because each pollutant has only one recorded value. PM1 sits at 1.289 µg/m³, while PM2.5 is measured at 2.245 µg/m³; both are reported with identical minimum, median and maximum figures. Relative humidity is logged as 62.13 % and temperature as 14.46 °C, again with a single point for each. The UM003 count stands at 209.51 particles per cubic centimetre, also without any variation.

Because the coverage consists of a single station, the dataset cannot capture spatial differences across Hayama or temporal changes beyond the most recent timestamp. Users should keep in mind that conditions may differ elsewhere in the town or shift after the last update, as no older or additional rows are available to illustrate trends or variability.

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 dataset for Hayama includes five valid measurements and was updated within three days, with the latest refresh recorded at 2026‑02‑10 23:00 UTC. These figures represent a snapshot of ambient conditions captured by the monitoring network; actual air quality can differ across neighborhoods and change throughout the day. Users should consider this variability when interpreting the displayed values.

OpenAQ station rows