Cities with the highest air pollution in Canada

Understanding where air quality is poor is as important as knowing where it is clean. This ranking reflects cities where ClearSpot's air quality module detects the highest modelled environmental pressure - whether from transport emissions, industrial zones, topography that traps pollutants, or persistent regional pollution patterns driven by meteorology and land use.

This data is not intended to discourage people from visiting or living in these cities. Local conditions vary enormously within any urban area, and many cities with challenging regional air quality have clean neighbourhoods, abundant parks, and lower-exposure residential zones. The ClearSpot live map lets you check any specific GPS coordinate, not just the city-centre average shown here.

Data is sourced from open government monitoring networks and the Copernicus Atmosphere Monitoring Service. It is refreshed monthly and represents average conditions over the reference period - not a worst-day reading.