Air quality in Koshigaya, Japan today

Mr. Duck’s Air Quality Score

Moderate air today for Koshigaya, 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 Koshigaya today falls into the Moderate category. The primary pollutant identified is PM2.5, with a measured concentration of 19.0 µg/m³ based on ten valid observations reported through OpenAQ.

No other pollutants have been highlighted for 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 Koshigaya air‑quality feed contains data for six pollutants – carbon monoxide (CO), nitrogen oxide (NO), nitrogen dioxide (NO₂), total nitrogen oxides (NOX), fine particulate matter (PM2.5) and sulfur dioxide (SO₂). The dataset comprises ten recent measurement rows collected from two monitoring sites in the city, so each station contributes multiple observations for most gases.

All values are current as of 2026‑02‑10 22:00 UTC, which falls within the “updated within three days” freshness window. For CO the single reading is 0.3 ppm, while SO₂ is recorded once at 0.001 ppm from a different location (越谷市東越谷３－１４). The remaining four pollutants have three rows each, all taken at 越谷市千間台西4‑2. NO varies between 0.003 and 0.004 ppm with a median of 0.0035 ppm; NO₂ is constant at 0.025 ppm across its three entries; NOX spans 0.028 to 0.029 ppm, centering on 0.0285 ppm; and PM2.5 ranges from 18.0 to 19.0 µg/m³ with a median of 18.5 µg/m³. The narrow spreads indicate limited variability among the recent samples.

Because only two stations contribute data, spatial coverage is modest and conditions can differ across other parts of Koshigaya that are not directly represented here. Nonetheless, the dataset provides a fresh snapshot of the city’s ambient air chemistry on the morning of 10 February 2026, with each pollutant reported at least once and most gases measured multiple times within the same hour.

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 reflects ten valid measurements and was updated within 3 days, with the most recent reading recorded at 2026‑02‑10T22:00:00+00:00. These values provide a snapshot of current conditions in Koshigaya, but air quality can differ across neighborhoods and change rapidly throughout the day, so local variations may not be captured by this summary.

OpenAQ station rows