What is the air quality trend in Washington?

Over the past 21 days, Washington had an average AQI of 66 based on station measurements. The worst day was 2026-05-10 with AQI 82.

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

462h

PM2.5 Station

462h · 2 stations

Temperature GFS model

80pt

Precipitation GFS model

mm/day

Daily Summary Station

Date	AQI	Range	PM2.5 avg	Hours	Stations
2026-05-29	45	13–76	12.0 µg/m³	16h	3
2026-05-28	51	8–137	14.2 µg/m³	21h	3
2026-05-27	55	16–142	16.6 µg/m³	23h	3
2026-05-26	72	11–185	25.9 µg/m³	23h	3
2026-05-25	61	18–156	18.6 µg/m³	24h	3
2026-05-24	61	21–122	18.2 µg/m³	22h	3
2026-05-23	71	21–223	26.3 µg/m³	24h	3
2026-05-22	78	9–182	27.5 µg/m³	24h	3
2026-05-21	78	20–242	31.3 µg/m³	24h	3
2026-05-20	74	18–161	24.6 µg/m³	24h	3
2026-05-19	76	21–176	28.9 µg/m³	24h	3
2026-05-18	77	18–147	25.4 µg/m³	23h	4
2026-05-17	67	21–133	20.7 µg/m³	22h	4
2026-05-16	62	21–123	18.4 µg/m³	21h	4
2026-05-15	68	18–216	24.7 µg/m³	23h	4
2026-05-14	73	18–142	23.4 µg/m³	24h	4
2026-05-13	65	17–246	24.3 µg/m³	24h	4
2026-05-12	49	19–82	13.3 µg/m³	24h	4
2026-05-11	76	21–242	32.9 µg/m³	24h	4
2026-05-10	82	32–222	30.4 µg/m³	23h	5
2026-05-09	54	31–89	15.2 µg/m³	5h	5

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