{"@context":"https://schema.org","@type":"Dataset","@id":"https://zipradar.org/topic/air-quality/21201/","name":"Air quality for ZIP 21201 — Baltimore, MD","description":"Air quality data for ZIP 21201 (Baltimore, Maryland), sourced from EPA Air Quality System (AQS), annual county summary.","topic":{"slug":"air-quality","label":"Air quality","source":"EPA Air Quality System (AQS), annual county summary","sourceUrl":"https://aqs.epa.gov/aqsweb/airdata/download_files.html","refreshCadence":"Annual (EPA AQS publication)","summary":"Pages show the 2025 median AQI category (Good, Moderate, Unhealthy for Sensitive Groups, Unhealthy, Very Unhealthy, Hazardous) for the ZIP's county, plus the year's max/90th-percentile AQI and day-count breakdown by category.","limitations":"This is a county-level ANNUAL SUMMARY, not a live current reading and not an address-level measurement — for today's AQI, EPA's real-time AirNow feed is the correct source (not yet federated here). Not every county operates an EPA monitor; absence of data for a ZIP's county means no 2025 EPA reading exists, not that air is good."},"place":{"zip":"21201","city":"Baltimore","state":"MD","stateFull":"Maryland","county":"Baltimore (city)","countySlug":"baltimore","geo":{"latitude":39.2959,"longitude":-76.6217}},"stateContext":{"topConcern":"Chesapeake flood, lead pipes","narrative":"Maryland has dense FEMA NFHL coverage along Chesapeake Bay tributaries. Baltimore City has extensive LCRR lead-service-line obligations and flagged EPA SDWIS compliance history. Radon Zone 1-2 across most counties."},"radonZone":null,"airQuality":{"year":2025,"medianAqi":43,"medianCategory":"Good","maxAqi":136,"p90Aqi":64,"daysWithAqi":364,"goodDays":248,"moderateDays":114,"usgDays":2,"unhealthyDays":0,"veryUnhealthyDays":0,"hazardousDays":0,"classification":"county-level ANNUAL summary — not a live current reading, not an address-level measurement","caveat":"This is a county-level ANNUAL SUMMARY for 2025, not a live current reading. For today's air quality, check a real-time monitor at airnow.gov. Categories follow EPA's official AQI breakpoints."},"waterQuality":null,"datePublished":"2026-04-24","dateModified":"2026-09-15","canonicalUrl":"https://zipradar.org/topic/air-quality/21201/","zipDashboardUrl":"https://zipradar.org/zip/21201/","zipDashboardApiUrl":"https://zipradar.org/api/zip/21201/","primarySourceUrl":"https://aqs.epa.gov/aqsweb/airdata/download_files.html","license":{"content":"CC-BY-4.0","attribution":"zipradar.org — https://zipradar.org/topic/air-quality/21201/"}}