Madrid air quality daily measurements and monitoring station metadata (2025-2026)

This dataset contains daily air quality measurements from the Madrid City Council open data portal, enriched with metadata from the official monitoring stations. The dataset was generated through a reproducible web-scraping pipeline based on public HTML pages, resource discovery, CSV download and transformation into a single analytical table. The current version covers observations from 2025-01-01 to 2026-02-28. The dataset contains 55,184 rows and 37 columns. Each row represents one date, one monitoring station and one pollutant, including both measurement values and station metadata such as location, altitude, station type and traceability fields. The dataset includes information from 24 monitoring stations and 11 pollutants. It is intended for academic use in data acquisition, data lifecycle, environmental analytics and reproducible research workflows. Files included:- madrid_air_quality_2025_2026.csv- source_audit.json- README_ZENODO.md Source datasets:- Madrid City Council Open Data Portal — “Calidad del aire. Estaciones de control”- Madrid City Council Open Data Portal — “Calidad del aire. Datos diarios desde 2001”