What is the air quality trend in Capitol Hill?

Over the past 3 days, Capitol Hill had an average AQI of 45 based on station measurements. The worst day was 2026-07-20 with AQI 65.

How is Capitol Hill air quality measured?

Air quality in Capitol Hill 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 Capitol Hill, United States

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

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

Current AQI
Good Station

48 Hours 7 Days 14 Days 20 Days

CSV JSON

Air Quality Index Station

48h

PM2.5 Station

48h · 1 station

Temperature GFS model

8pt

Precipitation GFS model

mm/day

Daily Summary Station

Date	AQI	Range	PM2.5 avg	Hours	Stations
2026-07-22	18	5–27	4.4 µg/m³	6h	26
2026-07-21	53	28–76	14.6 µg/m³	24h	28
2026-07-20	65	41–74	18.9 µg/m³	18h	29

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