Louisville Air Quality in 2024

In 2024, Louisville's air quality (Louisville/Jefferson County, KY-IN area) had a median daily AQI of 51 (Moderate) across 366 monitored days. 13 days (3.6%) reached Unhealthy for Sensitive Groups or worse, 173 were Good, and the year's peak AQI was 156 (Unhealthy). Fine particulate matter (PM2.5) set the daily AQI on 203 of those days. The cleanest month of 2024 was December (median AQI 43, 0 days above 100) and the worst was August (median 56, 6 days above 100, peak 150).

51
Median AQI
Moderate
13
Days above AQI 100
3.6% of 366 days
77
90th percentile AQI
worst 1 day in 10
156
Peak AQI
Unhealthy
PM2.5
Main pollutant
203 of 366 days
173
Good days
47.3% of days
  • Good: 47.3%
  • Moderate: 49.2%
  • Unhealthy for Sensitive Groups: 3.3%
  • Unhealthy or worse: 0.3%

Extra Protection for Louisville Homes

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QUICK ANSWER

How was Louisville's air quality in 2024?

Moderate on a typical day: median AQI 51, with 13 days above AQI 100 out of 366 monitored — the 6th cleanest of 7 years on record for the area.

  • Peak AQI in 2024: 156 (Unhealthy).
  • Fine particulate matter (PM2.5) was the main pollutant on 203 days.
  • Cleanest month: December; worst: August.

Frequently asked questions

What was the average AQI in Louisville in 2024?

EPA's Air Quality System puts Louisville's (Louisville/Jefferson County, KY-IN) median daily AQI for 2024 at 51, which is Moderate. 13 days were Unhealthy for Sensitive Groups or worse and the year's highest AQI was 156.

Which month had the worst air quality in Louisville in 2024?

The cleanest month of 2024 was December (median AQI 43, 0 days above 100) and the worst was August (median 56, 6 days above 100, peak 150).

Was 2024 a good or bad year for Louisville's air?

Among the 7 years EPA has published for the area (2019–2025), 2024 ranks 6th cleanest by days above AQI 100. 2024's median of 51 is below the area's typical annual median of 54.

Louisville month by month in 2024

Louisville air quality month by month, 2024 (Louisville/Jefferson County, KY-IN, EPA AQS daily AQI)

MonthDays monitoredMedian AQIDays above 100Peak AQIMain pollutant
January3144064PM2.5
February2951074PM2.5
March3147061PM2.5
April3047074O3
May3149097O3
June30594156O3
July31592136O3
Augustworst31566150O3
September30481108O3
October3156080PM2.5
November3049060PM2.5
Decembercleanest3143057PM2.5

How 2024 compares

Among the 7 years EPA has published for the area (2019–2025), 2024 ranks 6th cleanest by days above AQI 100.

2024's median of 51 is below the area's typical annual median of 54.

Activity-specific thresholds: running, cycling, kids' sports.

Right now in Louisville

The latest EPA AirNow observation puts Louisville's AQI at 61 (PM2.5). The figures above are multi-year annual statistics, not today's reading.

View current Louisville air quality →

Source: EPA Air Quality System (AQS) pre-generated Daily AQI by CBSA files — daily AQI by CBSA (Louisville/Jefferson County, KY-IN), 2019–2025. Daily AQI per CBSA is the highest AQI reported by any monitor in the area that day; the defining parameter is the pollutant that set it. Month and season statistics pool every such day in the period across all years listed. Retrieved 2026-09-09.