Air quality in Chiba, Japan today

Mr. Duck’s Air Quality Score

Good air today for Chiba, 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 Chiba is currently rated as Good. The main pollutant identified is PM2.5, with a measured concentration of 5.08 µg/m³ based on 45 valid observations reported through OpenAQ.

Overall conditions meet the Good classification, and the available data show no additional pollutants exceeding reference values. 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 OpenAQ feed for Chiba currently contains data from ten monitoring stations, amounting to a total of forty‑six individual rows across all measured pollutants. The dataset includes carbon monoxide (CO), nitrogen oxide (NO), nitrogen dioxide (NO₂), combined nitrogen oxides (NOX), fine particulate matter (PM2.5) and sulfur dioxide (SO₂). Across the board the most recent observations were recorded on 2026‑02‑10, with timestamps ranging from 22:00 UTC for the gas species to 22:58 UTC for PM2.5, indicating that the newest values are less than a day old.

PM2.5 is reported in micrograms per cubic metre and shows a median concentration of 6.5 µg/m³, with individual readings spanning from a low of 3.0 to a high of 12.0 µg/m³; the 10th‑percentile sits at 4.8 and the 90th‑percentile at about 8.4. The gas measurements are generally lower in magnitude: CO ranges between 0.2 and 0.3 ppm (median 0.25 ppm), NO is capped at 0.001 ppm, NO₂ varies from 0.004 to 0.013 ppm (median 0.007 ppm) and NOX extends slightly higher to a maximum of 0.014 ppm (median 0.007 ppm). Sulfur dioxide is the least variable, with values between 0.0 and 0.002 ppm and a median of 0.001 ppm.

Coverage across pollutants is uneven: while PM2.5 has ten recent rows, CO is represented by only two rows, and SO₂ by seven. Most gas‑type observations were last updated at the same moment (2026‑02‑10 22:00 UTC), whereas PM2.5 benefits from a slightly later update. Because the dataset relies on a limited number of stations and some pollutants have very few recent entries, conditions in different parts of Chiba may not be fully captured at any given moment.

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 45 valid measurements and is Updated within 3 days, with the most recent reading recorded on 2026‑02‑10 at 22:58 UTC. This snapshot provides a current view of air quality across Chiba, but conditions can differ by neighborhood and time of day, so values may vary throughout the city.

OpenAQ station rows