Insights: Bridgeport-Stamford-Norwalk, CT metro. Aggregated EPA AQS monitors across this Core-Based Statistical Area logged a median Air Quality Index of 44 over 181 measured days in 2025, which corresponds to a Good band and a Moderate metro-wide health grade. The monitored-day split lands at 121 Good days (67%), 51 Moderate (28%), and 8 Unhealthy-for-Sensitive-Groups (4%). The 90th-percentile AQI finished at 69 while the highest single-day reading hit 166 (Unhealthy). Metro residents averaged roughly 20.1 clean-air days per 30-day window across the reporting year.

Across the 2020–2025 trend window, good days shifted by -96 and the median AQI moved -3 points, which classifies the multi-year trajectory as improving. 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 Athens-Clarke County, GA (66.7% good, AQI 44); Bartlesville, OK (65.6% good, AQI 44); Bloomington, IL (64.1% good, AQI 44).