Louisville Air Quality in 2023
In 2023, Louisville's air quality (Louisville/Jefferson County, KY-IN area) had a median daily AQI of 55 (Moderate) across 365 monitored days. 21 days (5.8%) reached Unhealthy for Sensitive Groups or worse, 117 were Good, and the year's peak AQI was 182 (Unhealthy). Fine particulate matter (PM2.5) set the daily AQI on 260 of those days. The cleanest month of 2023 was October (median AQI 50, 0 days above 100) and the worst was June (median 96, 12 days above 100, peak 182).
- Good: 32.1%
- Moderate: 62.2%
- Unhealthy for Sensitive Groups: 5.5%
- Unhealthy or worse: 0.3%
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How was Louisville's air quality in 2023?
Moderate on a typical day: median AQI 55, with 21 days above AQI 100 out of 365 monitored — the 7th cleanest of 7 years on record for the area.
- ✓Peak AQI in 2023: 182 (Unhealthy).
- ✓Fine particulate matter (PM2.5) was the main pollutant on 260 days.
- ✓Cleanest month: October; worst: June.
Frequently asked questions
What was the average AQI in Louisville in 2023?▾
EPA's Air Quality System puts Louisville's (Louisville/Jefferson County, KY-IN) median daily AQI for 2023 at 55, which is Moderate. 21 days were Unhealthy for Sensitive Groups or worse and the year's highest AQI was 182.
Which month had the worst air quality in Louisville in 2023?▾
The cleanest month of 2023 was October (median AQI 50, 0 days above 100) and the worst was June (median 96, 12 days above 100, peak 182).
Was 2023 a good or bad year for Louisville's air?▾
Among the 7 years EPA has published for the area (2019–2025), 2023 ranks 7th cleanest by days above AQI 100 — the worst year on record here. 2023's median of 55 is in line with the area's typical annual median of 54.
Louisville month by month in 2023
Louisville air quality month by month, 2023 (Louisville/Jefferson County, KY-IN, EPA AQS daily AQI)
| Month | Days monitored | Median AQI | Days above 100 | Peak AQI | Main pollutant |
|---|---|---|---|---|---|
| January | 31 | 56 | 0 | 72 | PM2.5 |
| February | 28 | 55 | 0 | 72 | PM2.5 |
| March | 31 | 54 | 0 | 91 | PM2.5 |
| April | 30 | 55 | 0 | 100 | O3 |
| May | 31 | 55 | 1 | 101 | O3 |
| Juneworst | 30 | 96 | 12 | 182 | PM2.5 |
| July | 31 | 58 | 5 | 122 | PM2.5 |
| August | 31 | 58 | 3 | 150 | PM2.5 |
| September | 30 | 55 | 0 | 74 | PM2.5 |
| Octobercleanest | 31 | 50 | 0 | 67 | PM2.5 |
| November | 30 | 58 | 0 | 96 | PM2.5 |
| December | 31 | 52 | 0 | 70 | PM2.5 |
How 2023 compares
Among the 7 years EPA has published for the area (2019–2025), 2023 ranks 7th cleanest by days above AQI 100 — the worst year on record here.
2023's median of 55 is in line with 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 36 (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.