Air quality in Koshu, Japan today
Mr. Duck’s Air Quality Score
Good air today for Koshu, 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 Koshu is rated as Good today. The main pollutant identified is PM2.5, with a measured concentration of 9.0 µg/m³ based on four valid observations reported through OpenAQ.
Overall conditions meet the Good category criteria, and no other pollutants are highlighted in this assessment. 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 air‑quality feed for Koshu currently includes four measured pollutants – nitrogen monoxide (NO), nitrogen dioxide (NO₂), total nitrogen oxides (NOX) and fine particulate matter (PM2.5). All of these values come from a single monitoring location at 甲州市塩山上塩後１２３９－１, so the dataset represents one station rather than a network across the city.
Each pollutant has only one recorded value, which also serves as its minimum, median and maximum for the period covered. NO is reported at 0.001 ppm, NO₂ at 0.005 ppm, NOX at 0.006 ppm and PM2.5 at 9.0 µg/m³. Because there is no variation among the recorded points, the spread (10th‑percentile to 90th‑percentile) is identical to the single value for every pollutant.
The most recent measurement timestamp for all four parameters is 2026-02-10 22:00 UTC, and each entry is flagged as “Updated within 3 days.” This indicates that the data are fresh, with no older or unknown timestamps in the current set. However, because only one station contributes data, the snapshot may not capture spatial differences that can occur elsewhere in Koshu.
In summary, the dataset provides a very limited view: four pollutants from one site, all measured at the same recent moment and showing identical min‑median‑max values. While the timestamps are current, the lack of multiple stations or repeated observations means the picture of air quality across the broader city area remains incomplete.
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 for Koshu reflects four valid measurements and was refreshed recently, with the latest update recorded on 2026‑02‑10 at 22:00 UTC, meaning it is updated within three days. These figures provide a snapshot of current conditions, but air quality can differ across neighborhoods and change throughout the day, so local variations may not be captured in this summary.
OpenAQ station rows
| Station | Parameter | Value | Unit | Last updated |
|---|---|---|---|---|
| 甲州市塩山上塩後１２３９－１ | no | 0.001 | ppm | 2026-02-10 22:00 UTC |
| 甲州市塩山上塩後１２３９－１ | no2 | 0.005 | ppm | 2026-02-10 22:00 UTC |
| 甲州市塩山上塩後１２３９－１ | nox | 0.006 | ppm | 2026-02-10 22:00 UTC |
| 甲州市塩山上塩後１２３９－１ | pm25 | 9.0 | µg/m³ | 2026-02-10 22:00 UTC |