Insights: Louisville/Jefferson County, KY-IN metro. Aggregated EPA AQS monitors across this Core-Based Statistical Area logged a median Air Quality Index of 52 over 365 measured days in 2025, which corresponds to a Moderate band and a Poor metro-wide health grade. The monitored-day split lands at 161 Good days (44%), 194 Moderate (53%), and 9 Unhealthy-for-Sensitive-Groups (2%). The 90th-percentile AQI finished at 71 while the highest single-day reading hit 153 (Unhealthy). Metro residents averaged roughly 13.2 clean-air days per 30-day window across the reporting year.

Across the 2020–2025 trend window, the share of monitored days rated Good shifted by +5.1 points and the median AQI moved -1 points, which classifies the multi-year trajectory as improving. The annual record contains 1 day at Unhealthy or worse. On that day, the EPA recommends that sensitive groups limit prolonged outdoor exertion. Metros with comparable AQI profiles include Augusta-Richmond County, GA-SC (46.0% good, AQI 52); Beaumont-Port Arthur, TX (41.4% good, AQI 52); Birmingham-Hoover, AL (43.0% good, AQI 52).