RSQA - Air Quality Index (historical)

The City of Montreal measures air quality in the form of a numerical value called the “Air Quality Index (AQI).” This data set provides access to historical AQI values, updated daily.

***Note: ** The AQI systems do not change the time: they always use Eastern Standard Time (EST) and not Eastern Daylight Time (EDT). So during daylight savings time, there is a 1-hour time lag in the data. For example, a measurement recorded at 12 pm EST is that of 1 pm EDT. *

The daily values, updated every hour, are available [here] (rsqa-air-quality-index).

The [list of stations] (rsqa-liste-des-stations) and [sectors] (rsqa-geographic-sectors) linked to RSQA data is also available.

Organization: Government and Municipalities of Québec | Gouvernement et municipalités du Québec

Last modified: 2026-04-17T15:48:32.821066