What is the air quality trend in Guelph?

Over the past 8 days, Guelph had an average AQI of 50 based on station measurements. The worst day was 2026-05-25 with AQI 70.

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

167h

PM2.5 Station

167h · 9 stations

Temperature GFS model

28pt

Precipitation GFS model

mm/day

Daily Summary Station

Date	AQI	Range	PM2.5 avg	PM10 avg	Hours	Stations
2026-05-30	48	23–152	13.4 µg/m³	2.5	12h	12
2026-05-29	50	10–121	14.4 µg/m³	7.4	24h	16
2026-05-28	40	12–155	11.4 µg/m³	2.1	24h	14
2026-05-27	55	18–155	16.1 µg/m³	5.7	24h	13
2026-05-26	35	19–68	8.5 µg/m³	5.8	24h	12
2026-05-25	70	18–169	25.0 µg/m³	11.2	24h	14
2026-05-24	50	18–93	13.7 µg/m³	5.1	24h	16
2026-05-23	55	32–127	15.5 µg/m³	2.3	11h	13

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