What is the air quality trend in Ellicott City?

Over the past 15 days, Ellicott City had an average AQI of 25 based on station measurements. The worst day was 2026-10-14 with AQI 40.

How is Ellicott City air quality measured?

Air quality in Ellicott City 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 Ellicott City, United States

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

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

Current AQI
Good Station

48 Hours 7 Days 14 Days 20 Days

CSV JSON

Air Quality Index Station

333h

PM2.5 Station

333h · 20 stations

Temperature GFS model

56pt

Precipitation GFS model

mm/day

Daily Summary Station

Date	AQI	Range	PM2.5 avg	Hours	Stations
2026-10-21	25	25–25	5.9 µg/m³	2h	20
2026-10-20	23	18–32	5.4 µg/m³	24h	18
2026-10-19	26	18–33	6.1 µg/m³	24h	20
2026-10-18	18	16–26	4.4 µg/m³	24h	18
2026-10-17	15	11–23	3.7 µg/m³	24h	19
2026-10-16	30	16–49	7.1 µg/m³	24h	19
2026-10-15	30	18–55	7.2 µg/m³	24h	20
2026-10-14	40	35–47	9.6 µg/m³	24h	19
2026-10-13	26	18–35	6.2 µg/m³	24h	18
2026-10-12	16	10–26	3.7 µg/m³	24h	19
2026-10-11	17	12–24	4.2 µg/m³	24h	22
2026-10-10	33	23–50	7.9 µg/m³	24h	19
2026-10-09	26	18–34	6.3 µg/m³	24h	20
2026-10-08	27	20–36	6.5 µg/m³	24h	22
2026-10-07	24	15–29	5.8 µg/m³	19h	20

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