Air quality in Santiago do Cacém, Portugal today
Mr. Duck’s Air Quality Score
Good air today for Santiago do Cacém, Portugal
This friendly indicator summarizes the latest city readings. For health guidance, please see: EPA AirNow or WHO.
Air quality today
The air quality in Santiago do Cacém is currently classified as Good. The main pollutant identified is PM2.5, based on five valid measurements collected and reported through OpenAQ. This assessment reflects the most recent data available for the city.
According to the data shown via OpenAQ, the PM2.5 concentration is 1.3 µg/m³ and the PM10 concentration is 14.9 µg/m³. Both values are expressed in micrograms per cubic meter and represent the latest recorded levels for the monitoring period. The dataset includes five valid observations that support the current classification. These concentrations are consistent with the Good category rating. 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 Santiago do Cacém contains six measured pollutants – carbon monoxide, nitrogen dioxide, ozone, particulate matter 10, particulate matter 2.5 and sulphur dioxide – each represented by a single row of data from one monitoring station. Because there is only one station, the overall coverage is limited to these six observations, and every pollutant shows the same minimum, median and maximum value, meaning the record reflects a single snapshot rather than a range of measurements over time.
Freshness of the data differs across the pollutants. Carbon monoxide, ozone, particulate matter 2.5 and sulphur dioxide were last updated on 2026‑02‑10 21:00 UTC, which places them well within the most recent 30‑day window. In contrast, nitrogen dioxide and particulate matter 10 were last refreshed on 2026‑01‑24 01:00 UTC; although still within a month of the current date, these entries are flagged as older. This split indicates that half of the available measurements are very recent while the other half are slightly less current.
The numeric values themselves are straightforward: carbon monoxide registers at 103.0 µg/m³, ozone at 56.0 µg/m³, particulate matter 2.5 at 1.3 µg/m³ and particulate matter 10 at 14.9 µg/m³. Nitrogen dioxide reads 0.0 µg/m³, and sulphur dioxide shows –1.0 µg/m³, a negative figure that typically signals a sensor anomaly rather than a physical concentration. Because the dataset consists of only one reading per pollutant, there is no observed variability or trend, and the presence of the anomalous sulphur dioxide value highlights the need to treat that particular entry with caution when interpreting the city’s air‑quality picture.
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 dataset for Santiago do Cacém includes five valid measurements and is updated within 30 days. The latest data were recorded on 2026-02-10 at 21:00 UTC. This snapshot reflects conditions at the time of sampling; air quality can vary by location and time within the city. Users should consider these limitations when interpreting the values.
OpenAQ station rows
| Station | Parameter | Value | Unit | Last updated |
|---|---|---|---|---|
| Santiago do Cacém | co | 103.0 | µg/m³ | 2026-02-10 21:00 UTC |
| Santiago do Cacém | no2 | 0.0 | µg/m³ | 2026-01-24 01:00 UTC |
| Santiago do Cacém | o3 | 56.0 | µg/m³ | 2026-02-10 21:00 UTC |
| Santiago do Cacém | pm10 | 14.9 | µg/m³ | 2026-01-24 01:00 UTC |
| Santiago do Cacém | pm25 | 1.3 | µg/m³ | 2026-02-10 21:00 UTC |