What is the air quality trend in Toronto?

Over the past 3 days, Toronto had an average AQI of 45 based on station measurements. The worst day was 2026-05-29 with AQI 50.

How is Toronto air quality measured?

Air quality in Toronto is measured by ground-level monitoring stations that report PM2.5 and PM10 concentrations hourly. CERNS.IO aggregates readings from nearby stations and converts PM2.5 to the US EPA Air Quality Index (AQI) scale.

Air Quality History for Toronto, Canada

Name: Toronto Air Quality History
Creator: CERNS.IO
License: https://creativecommons.org/licenses/by/4.0/

Historical PM2.5 and AQI trend from monitoring stations near Toronto, Canada.

Current AQI
Good Station

48 Hours 7 Days 14 Days 20 Days

CSV JSON

Air Quality Index Station

47h

PM2.5 Station

47h · 10 stations

Temperature GFS model

7pt

Precipitation GFS model

mm/day

Daily Summary Station

Date	AQI	Range	PM2.5 avg	PM10 avg	Hours	Stations
2026-05-30	47	21–157	14.0 µg/m³	1.8	12h	13
2026-05-29	50	15–128	14.1 µg/m³	12.1	24h	17
2026-05-28	38	15–70	9.9 µg/m³	1.2	11h	14

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