Air quality in Rancagua, Chile today

Mr. Duck’s Air Quality Score

Moderate air today for Rancagua, Chile

⚠️ 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 Rancagua is currently classified as Moderate. The primary pollutant identified is PM2.5 (fine particles).

Measurements from five valid monitoring stations show a PM2.5 reference value of 17.0 and a PM10 reference value of 41.0, according to OpenAQ 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

The dataset for Rancagua contains measurements of carbon monoxide (CO), nitrogen dioxide (NO₂), ozone (O₃), particulate matter ≤ 10 µm (PM10), particulate matter ≤ 2.5 µm (PM2.5) and sulphur dioxide (SO₂). Twelve individual rows are recorded across two monitoring stations, labelled Rancagua I and Rancagua II.

The freshness of the data varies markedly between pollutants. The most recent CO reading – 874.23 µg/m³ – was logged on 2021‑08‑20 20:00 UTC at Rancagua I, while NO₂ and O₃ both show their latest values (0.0 µg/m³) from 2017‑06‑28 16:00 UTC, indicating that these gases have not been updated for several years. In contrast, PM10, PM2.5 and SO₂ are current, with the newest entries dated 2026‑02‑10 (13:00 UTC for PM10 and PM2.5, 11:00 UTC for SO₂) from Rancagua II for the particulates and Rancagua I for sulphur dioxide.

The numeric spread also differs across the suite of pollutants. CO exhibits a very wide range, from a minimum of 0.0 up to a maximum of 874.23 µg/m³, with a median of 437.12 µg/m³ and the 10th‑90th percentile band stretching between roughly 87 and 787 µg/m³. Particulate matter shows a much tighter distribution: PM10 values range from 41 to 53 µg/m³ (median 47 µg/m³), while PM2.5 varies between 14 and 17 µg/m³ (median 15.5 µg/m³). SO₂ is recorded between 0.0 and 13.81 µg/m³, with a median of 6.91 µg/m³.

Overall the dataset provides recent information for particulates and sulphur dioxide but relies on outdated measurements for CO, NO₂ and O₃. Because only two stations contribute data, conditions in other parts of Rancagua may differ from what is captured here, especially for the gases with older timestamps.

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 Rancagua is based on five valid measurements and was refreshed recently, with the latest update recorded on 2026‑02‑10 at 13:00 UTC; it is considered “Updated within 3 days.” This snapshot reflects conditions at the time of collection, but air quality can vary across different neighborhoods and moments throughout the day, so values may differ locally.

OpenAQ station rows