What is the air quality trend in Ancaster?

Over the past 4 days, Ancaster had an average AQI of 138 based on station measurements. The worst day was 2026-07-17 with AQI 314.

How is Ancaster air quality measured?

Air quality in Ancaster 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 Ancaster, Canada

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

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

Current AQI
Good Station

48 Hours 7 Days 14 Days 20 Days

CSV JSON

Air Quality Index Station

16h

PM2.5 Station

16h · 5 stations

Temperature GFS model

28pt

Precipitation GFS model

mm/day

Daily Summary Station

Date	AQI	Range	PM2.5 avg	Hours	Stations
2026-07-20	46	26–95	13.5 µg/m³	6h	5
2026-07-19	78	29–161	30.4 µg/m³	4h	5
2026-07-18	115	31–189	67.4 µg/m³	4h	5
2026-07-17	314	312–315	266.2 µg/m³	2h	5

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