What is the air quality trend in Alliston?

Over the past 15 days, Alliston had an average AQI of 41 based on station measurements. The worst day was 2026-05-18 with AQI 56.

How is Alliston air quality measured?

Air quality in Alliston 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 Alliston, Canada

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

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

Current AQI
Good Station

48 Hours 7 Days 14 Days 20 Days

CSV JSON

Air Quality Index Station

336h

PM2.5 Station

336h · 6 stations

Temperature GFS model

56pt

Precipitation GFS model

mm/day

Daily Summary Station

Date	AQI	Range	PM2.5 avg	Hours	Stations
2026-05-30	26	16–40	6.3 µg/m³	9h	5
2026-05-29	40	10–120	10.6 µg/m³	24h	7
2026-05-28	29	13–81	7.2 µg/m³	24h	7
2026-05-27	38	14–94	10.3 µg/m³	24h	6
2026-05-26	42	25–85	11.1 µg/m³	24h	6
2026-05-25	53	18–160	16.0 µg/m³	24h	7
2026-05-24	33	11–101	9.0 µg/m³	24h	7
2026-05-23	51	15–169	15.3 µg/m³	24h	8
2026-05-22	32	11–72	8.4 µg/m³	24h	6
2026-05-21	44	14–91	11.9 µg/m³	24h	8
2026-05-20	48	11–148	13.4 µg/m³	24h	6
2026-05-19	38	18–117	10.1 µg/m³	24h	6
2026-05-18	56	28–161	16.8 µg/m³	24h	6
2026-05-17	52	30–75	14.0 µg/m³	24h	4
2026-05-16	37	22–64	9.4 µg/m³	15h	7

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