What is the air quality trend in Guelph?

Over the past 3 days, Guelph had an average AQI of 42 based on station measurements. The worst day was 2026-05-29 with AQI 50.

How is Guelph air quality measured?

Air quality in Guelph 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 Guelph, Canada

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

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

Current AQI
Good Station

48 Hours 7 Days 14 Days 20 Days

CSV JSON

Air Quality Index Station

47h

PM2.5 Station

47h · 11 stations

Temperature GFS model

8pt

Precipitation GFS model

mm/day

Daily Summary Station

Date	AQI	Range	PM2.5 avg	PM10 avg	Hours	Stations
2026-05-30	39	9–72	10.4 µg/m³	2.6	11h	11
2026-05-29	50	10–121	14.2 µg/m³	7.4	24h	14
2026-05-28	37	12–87	9.5 µg/m³	1.6	12h	11

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