What is the air quality trend in Washington?

Over the past 21 days, Washington had an average AQI of 43 based on station measurements. The worst day was 2026-08-26 with AQI 72.

How is Washington air quality measured?

Air quality in Washington 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 Washington, United Kingdom

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

Historical PM2.5 and AQI trend from monitoring stations near Washington, United Kingdom.

Current AQI
Good CAMS model

48 Hours 7 Days 14 Days 20 Days

CSV JSON

Air Quality Index Station

332h

PM2.5 Station

332h · 1 station

Temperature GFS model

80pt

Precipitation GFS model

mm/day

Daily Summary Station

Date	AQI	Range	PM2.5 avg	Hours	Stations
2026-09-05	30	20–51	7.1 µg/m³	9h	1
2026-09-04	46	17–90	12.2 µg/m³	19h	1
2026-09-03	45	8–98	12.7 µg/m³	16h	2
2026-09-02	39	8–67	9.8 µg/m³	16h	2
2026-09-01	46	10–152	12.8 µg/m³	18h	2
2026-08-31	35	10–57	8.5 µg/m³	19h	1
2026-08-30	41	10–93	10.9 µg/m³	16h	2
2026-08-29	51	2–156	15.4 µg/m³	18h	1
2026-08-28	43	8–88	11.6 µg/m³	15h	1
2026-08-27	58	22–164	18.3 µg/m³	17h	1
2026-08-26	72	38–164	23.5 µg/m³	16h	2
2026-08-25	52	24–84	14.5 µg/m³	16h	2
2026-08-24	36	17–61	9.0 µg/m³	14h	2
2026-08-23	35	21–59	8.6 µg/m³	16h	1
2026-08-22	45	13–159	12.9 µg/m³	18h	1
2026-08-21	48	9–73	12.6 µg/m³	16h	2
2026-08-20	55	12–120	16.4 µg/m³	17h	2
2026-08-19	39	6–185	14.3 µg/m³	16h	1
2026-08-18	33	3–62	8.3 µg/m³	16h	2
2026-08-17	33	16–54	8.0 µg/m³	19h	1
2026-08-16	35	18–48	8.3 µg/m³	5h	2

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