Air quality · ZIP 21401
Air quality in Annapolis, MD
ZIP 21401 (Maryland) — air quality summary sourced from EPA AirNow. Refreshed on the cadence of the primary regulator with every claim cited to the source record.
What lands here
Pages show the current AQI category (Good, Moderate, Unhealthy for Sensitive Groups, Unhealthy, Very Unhealthy, Hazardous), the nearest reporting station, and historical averages.
Source & refresh
EPA AirNow. Refreshed hourly real-time / daily historical. Stale data is flagged, never silently served. Primary source →
Limitations specific to this source
Rural ZIPs may not have a nearby monitoring station; zipradar then reports the closest available station with distance context.
Maryland context
Chesapeake flood, lead pipes
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.
See Maryland state page for the full state-level rollup across all 12 dimensions.
Read more on air quality
Editorial deep-dives explaining the source data, its limits, and how to read it.
AQI explained — what 50, 100, 150 actually mean for your lungs
Plain-English guide to the EPA Air Quality Index (AQI) and the 6 categories from Good to Hazardous. When to take precautions and which pollutants matter.
Wildfire Hazard Potential — what the USFS scale means and how to defend your home
Plain-English guide to the USDA Forest Service's Wildfire Hazard Potential 1–5 scale, how to read your community's risk, and concrete home-defense measures.
AirNow + wildfire smoke — when AQI is a real-time tool
How EPA AirNow handles real-time wildfire smoke, what the colors mean during fire season, and where AirNow leaves gaps you should know about.
AQI thresholds — what 'unhealthy for sensitive groups' actually means for you
EPA's AQI uses six bands keyed to specific population groups. Here's what each band means at the personal-decision level — go outside, mask, stay home.
Full dashboard for ZIP 21401
Air quality is one of twelve dimensions zipradar federates per address. See the full federated summary for ZIP 21401:
Open Annapolis, MD dashboard →