What is the air quality trend in Chicago Loop?

Over the past 9 days, Chicago Loop had an average AQI of 51 based on station measurements. The worst day was 2026-07-16 with AQI 142.

How is Chicago Loop air quality measured?

Air quality in Chicago Loop 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 Chicago Loop, United States

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

Historical PM2.5 and AQI trend from monitoring stations near Chicago Loop, United States.

Current AQI
Good Station

48 Hours 7 Days 14 Days 20 Days

CSV JSON

Air Quality Index Station

124h

PM2.5 Station

124h · 1 station

Temperature GFS model

80pt

Precipitation GFS model

mm/day

Daily Summary Station

Date	AQI	Range	PM2.5 avg	Hours	Stations
2026-07-21	33	3–99	9.8 µg/m³	18h	1
2026-07-20	51	23–96	14.2 µg/m³	24h	1
2026-07-19	43	14–85	11.9 µg/m³	24h	1
2026-07-18	13	3–32	3.2 µg/m³	18h	1
2026-07-17	107	22–167	39.3 µg/m³	24h	1
2026-07-16	142	101–188	63.2 µg/m³	11h	1
2026-07-06	30	30–30	7.1 µg/m³	1h	269
2026-07-03	2	2–2	0.4 µg/m³	1h	1
2026-07-02	40	29–54	9.7 µg/m³	3h	90

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