Air quality in San Sebastián de los Reyes, Community of Madrid, Spain today

Mr. Duck’s Air Quality Score

Good air today for San Sebastián de los Reyes, Community of Madrid, Spain

⚠️ 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 San Sebastián de los Reyes is classified as Good today. The primary pollutant identified is PM10, with a measured reference value of 11.0 micrograms per cubic metre based on six valid observations reported through OpenAQ.

PM10 levels are the only specific concentration provided for this assessment, and no other pollutants are highlighted in the current data set. 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 San Sebastián de los Reyes contains measurements for four pollutants – nitrogen monoxide (NO), nitrogen dioxide (NO₂), ozone (O₃) and particulate matter 10 µm or less (PM₁₀). The information comes from seven individual rows of sensor data, all recorded at a single monitoring site in the city. For three of the pollutants (NO₂, O₃ and PM₁₀) the most recent values were uploaded on 2026‑02‑09 at 15:00 UTC, which means they are fresh and fall within the “updated within seven days” category. The NO reading is older, last reported on 2024‑02‑28 at 23:00 UTC, and is therefore classified as old data.

Across the recent measurements the observed ranges are narrow. NO₂ values span from a minimum of 6.0 µg/m³ to a maximum of 9.0 µg/m³, with a median of 7.5 µg/m³; the 10th and 90th percentiles sit at 6.3 and 8.7 µg/m³ respectively, indicating limited variability during the reporting period. Ozone shows a similarly tight band, ranging from 58.0 to 63.0 µg/m³, median 60.5 µg/m³, with the central 80 % of observations between 58.5 and 62.5 µg/m³. PM₁₀ is constant at 11.0 µg/m³ for all rows, giving no spread to assess. NO, by contrast, has only a single recorded value of 7.0 µg/m³, reflecting the older timestamp and lack of recent updates.

Overall the data set provides a snapshot that is current for three key pollutants but limited for NO due to its outdated entry. Because all measurements come from one location, they represent conditions at that specific site rather than the full spatial diversity of San Sebastián de los Reyes, and temporal coverage varies: most values are fresh, yet the older NO reading highlights that not every pollutant is monitored with the same frequency.

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 are based on six valid measurements and were refreshed recently, with the latest update recorded at 2026‑02‑09T15:00:00+00:00 (Updated within 3 days). This snapshot reflects conditions captured across the monitoring network in San Sebastián de los Reyes, but air quality can vary by location and time within the city, so values may differ from those experienced elsewhere or at other moments.

OpenAQ station rows