This database compiles hourly ambient air quality readings for India from two monitoring networks: the Central Pollution Control Board's Continuous Ambient Air Quality Monitoring (CAAQM) network of 553 stations, with records from 2009 onwards, and the five air quality monitors operated by the US Embassy and Consulates in New Delhi, Mumbai, Kolkata, Chennai and Hyderabad, published by the US Department of State via AirNow, from July 2019 onwards. It holds about 196 million readings across 15 pollutants, including PM2.5, PM10, NO2, SO2, CO, ozone, ammonia and benzene, in one harmonised table with station coordinates. Readings are published as received from the source networks, with no gap filling or outlier removal.
The database is a living resource, updated frequently as the monitoring networks publish new readings, so the most recent months sit alongside the historical archive. It aims to make India's monitoring record usable as a single, well-documented and continuously maintained time series rather than hundreds of separately downloaded files, for researchers studying pollution exposure and its health and economic consequences, for government analysts evaluating air quality policy, and for journalists reporting on pollution episodes as they unfold. Data are available through a query API that returns filtered or aggregated slices in JSON, CSV or Parquet, and as bulk Parquet files for whole-archive analysis. A Google Colab notebook demonstrates typical use.
Citation:
Patnaik, Ayush (2026). India Air Quality Database. XKDR Forum
