Air quality in Katori, Japan today
Mr. Duck’s Air Quality Score
Good air today for Katori, Japan
This friendly indicator summarizes the latest city readings. For health guidance, please see: EPA AirNow or WHO.
Air quality today
The air quality in Katori is classified as Good today. The primary pollutant identified is PM2.5 (fine particles).
Measurements show a PM2.5 concentration of 7.0 µg/m³, based on five valid observations recorded by OpenAQ. This indicates that the fine particle level aligns with the reference value provided for this pollutant.
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 Katori includes five measured pollutants – nitrogen monoxide (NO), nitrogen dioxide (NO₂), combined nitrogen oxides (NOX), fine particulate matter (PM2.5) and sulfur dioxide (SO₂). All of these come from a single monitoring location at 香取市羽根川５５－５, so the station count is one row for each pollutant. The most recent reading for every compound was recorded on 2026-02-10 22:00 UTC, which falls within the “updated within 3 days” window and therefore represents a very fresh snapshot of current air quality in the city.
Across the five pollutants the observed values are identical for each measurement period, giving a clear picture of the immediate conditions at the monitoring site. NO is reported at 0.001 ppm, NO₂ at 0.004 ppm, NOX at 0.005 ppm and SO₂ at 0.0 ppm; PM2.5 registers 7.0 µg/m³. Because there is only one row per pollutant, the statistical spread is zero – the minimum, median, 10th percentile, 90th percentile and maximum are all the same as the single recorded value. This lack of variation means the dataset cannot describe any temporal or spatial fluctuations within Katori; it simply reflects the state at a single point in time.
The coverage therefore is limited to one fixed site, and while the data are up‑to‑date, they do not capture differences that might exist across neighborhoods or over longer periods. Users should keep in mind that conditions elsewhere in the city could differ from those recorded at 香取市羽根川５５－５, especially since no historical rows are available to show trends or changes beyond this latest measurement.
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 for Katori are based on five valid measurements and were refreshed recently, with the latest update recorded at 2026‑02‑10T22:00:00+00:00 (Updated within 3 days). These readings provide a snapshot of current conditions, but air quality can differ across neighborhoods and change throughout the day. Use this information as a general guide rather than a precise indicator for any specific location or moment.
OpenAQ station rows
| Station | Parameter | Value | Unit | Last updated |
|---|---|---|---|---|
| 香取市羽根川５５－５ | no | 0.001 | ppm | 2026-02-10 22:00 UTC |
| 香取市羽根川５５－５ | no2 | 0.004 | ppm | 2026-02-10 22:00 UTC |
| 香取市羽根川５５－５ | nox | 0.005 | ppm | 2026-02-10 22:00 UTC |
| 香取市羽根川５５－５ | pm25 | 7.0 | µg/m³ | 2026-02-10 22:00 UTC |
| 香取市羽根川５５－５ | so2 | 0.0 | ppm | 2026-02-10 22:00 UTC |