What is the air quality trend in Norwalk?

Over the past 8 days, Norwalk had an average AQI of 81 based on station measurements. The worst day was 2026-07-17 with AQI 111.

How is Norwalk air quality measured?

Air quality in Norwalk 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 Norwalk, United States

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

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

Current AQI
Good Station

48 Hours 7 Days 14 Days 20 Days

CSV JSON

Air Quality Index Station

168h

PM2.5 Station

168h · 5 stations

Temperature GFS model

28pt

Precipitation GFS model

mm/day

Daily Summary Station

Date	AQI	Range	PM2.5 avg	PM10 avg	Hours	Stations
2026-07-21	60	35–94	17.0 µg/m³	109.4	20h	7
2026-07-20	66	28–96	20.0 µg/m³	149.0	24h	8
2026-07-19	68	48–85	20.2 µg/m³	102.8	24h	9
2026-07-18	99	77–148	34.3 µg/m³	125.2	24h	9
2026-07-17	111	38–169	42.8 µg/m³	122.2	24h	10
2026-07-16	96	56–165	34.2 µg/m³	138.1	24h	9
2026-07-15	67	28–131	20.8 µg/m³	104.2	24h	7
2026-07-14	82	65–127	26.3 µg/m³	149.0	4h	6

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