Insights: Baltimore-Columbia-Towson, MD metro. Aggregated EPA AQS monitors across this Core-Based Statistical Area logged a median Air Quality Index of 47 over 366 measured days in 2024, which corresponds to a Good band and a Moderate metro-wide health grade. The monitored-day split lands at 215 Good days (59%), 139 Moderate (38%), and 11 Unhealthy-for-Sensitive-Groups (3%). The 90th-percentile AQI finished at 77 while the highest single-day reading hit 154 (Unhealthy). Metro residents averaged roughly 17.6 clean-air days per 30-day window across the reporting year.

Across the 2020–2024 trend window, good days shifted by -17 and the median AQI moved +1 points, which classifies the multi-year trajectory as worsening. The metro recorded 1 unhealthy-or-worse days combined, on those days the EPA recommends that sensitive groups limit prolonged outdoor exertion, and many schools and athletic programs adjust outdoor activity accordingly. Metros with comparable AQI profiles include Bartlesville, OK (57.2% good, AQI 47); Columbia, SC (57.4% good, AQI 47); Dayton, OH (59.6% good, AQI 47).