What is the air quality trend in London?

Over the past 5 days, London had an average AQI of 146 based on station measurements. The worst day was 2026-07-17 with AQI 423.

How is London air quality measured?

Air quality in London 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 London, Canada

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

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

Current AQI
Good Station

48 Hours 7 Days 14 Days 20 Days

CSV JSON

Air Quality Index Station

18h

PM2.5 Station

18h · 1 station

Temperature GFS model

28pt

Precipitation GFS model

mm/day

Daily Summary Station

Date	AQI	Range	PM2.5 avg	Hours	Stations
2026-07-21	40	34–46	9.6 µg/m³	2h	1
2026-07-20	82	65–102	27.0 µg/m³	6h	1
2026-07-19	106	76–171	44.6 µg/m³	4h	1
2026-07-18	80	30–176	35.5 µg/m³	4h	1
2026-07-17	423	408–438	403.7 µg/m³	2h	1

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