Air quality · Kentucky
Air quality in Kentucky
Across the 3 Kentucky ZIPs with EPA county air-quality data, the median day is Good in all 3 (median AQI 40–49). 1 day across those counties reached Unhealthy or worse in 2025. This is a 2025 county annual summary, not a live reading.
Last verified 2026-09-24 · methodology
Air quality by ZIP code in Kentucky
EPA's 2025 annual summary for each ZIP's county. Median AQI is the typical day; lower is cleaner.
| ZIP | Median AQI | Good days | Unhealthy or worse |
|---|---|---|---|
| 40202LouisvilleJefferson County | 49 Good | 188 of 365 | 1 |
| 40508Lexington (KY)Fayette County | 40 Good | 273 of 364 | 0 |
| 40503Lexington (KY)Fayette County | 40 Good | 273 of 364 | 0 |
County-level figures from EPA Air Quality System (AQS), annual county summary, joined to each ZIP by county. None of them is a measurement at a specific address.
What lands here
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.
Source & refresh
EPA Air Quality System (AQS), annual county summary. Refreshed annual (epa aqs publication). Primary source →
Kentucky top concern
Mining-affected water, flood (Ohio + tributaries)
Kentucky's Appalachian eastern counties face mining-affected water systems with elevated EPA SDWIS compliance risk. Ohio River + tributary FEMA AE zones expose Louisville, Owensboro, and Newport. Radon risk varies by karst geology.
See Kentucky state page for the full state-level rollup across all 12 dimensions.
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AQI explained — what 50, 100, 150 actually mean for your lungs
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AirNow + wildfire smoke — when AQI is a real-time tool
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