Louisville Air Quality in 2025
In 2025, Louisville's air quality (Louisville/Jefferson County, KY-IN area) had a median daily AQI of 52 (Moderate) across 365 monitored days. 10 days (2.7%) reached Unhealthy for Sensitive Groups or worse, 161 were Good, and the year's peak AQI was 153 (Unhealthy). Fine particulate matter (PM2.5) set the daily AQI on 230 of those days. The cleanest month of 2025 was October (median AQI 42, 0 days above 100) and the worst was September (median 58, 6 days above 100, peak 140).
- Good: 44.1%
- Moderate: 53.2%
- Unhealthy for Sensitive Groups: 2.5%
- Unhealthy or worse: 0.3%
Extra Protection for Louisville Homes
Air quality in Louisville is moderate (AQI 61), with fine particles (PM2.5) the main concern. A True-HEPA purifier gives sensitive groups — kids, seniors and anyone with asthma or allergies — cleaner air indoors on days like today.
Recommended: Coway AP-1512HH Mighty — True HEPA + carbon · CADR ~246 CFM · rooms up to 361 sq ft
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How was Louisville's air quality in 2025?
Moderate on a typical day: median AQI 52, with 10 days above AQI 100 out of 365 monitored — the 5th cleanest of 7 years on record for the area.
- ✓Peak AQI in 2025: 153 (Unhealthy).
- ✓Fine particulate matter (PM2.5) was the main pollutant on 230 days.
- ✓Cleanest month: October; worst: September.
Frequently asked questions
What was the average AQI in Louisville in 2025?▾
EPA's Air Quality System puts Louisville's (Louisville/Jefferson County, KY-IN) median daily AQI for 2025 at 52, which is Moderate. 10 days were Unhealthy for Sensitive Groups or worse and the year's highest AQI was 153.
Which month had the worst air quality in Louisville in 2025?▾
The cleanest month of 2025 was October (median AQI 42, 0 days above 100) and the worst was September (median 58, 6 days above 100, peak 140).
Was 2025 a good or bad year for Louisville's air?▾
Among the 7 years EPA has published for the area (2019–2025), 2025 ranks 5th cleanest by days above AQI 100. 2025's median of 52 is in line with the area's typical annual median of 54.
Louisville month by month in 2025
Louisville air quality month by month, 2025 (Louisville/Jefferson County, KY-IN, EPA AQS daily AQI)
| Month | Days monitored | Median AQI | Days above 100 | Peak AQI | Main pollutant |
|---|---|---|---|---|---|
| January | 31 | 52 | 0 | 82 | PM2.5 |
| February | 28 | 54 | 0 | 63 | PM2.5 |
| March | 31 | 52 | 0 | 77 | PM2.5 |
| April | 30 | 48 | 0 | 67 | O3 |
| May | 31 | 43 | 0 | 71 | O3 |
| June | 30 | 57 | 1 | 133 | PM2.5 |
| July | 31 | 56 | 3 | 153 | PM2.5 |
| August | 31 | 53 | 0 | 90 | O3 |
| Septemberworst | 30 | 58 | 6 | 140 | O3 |
| Octobercleanest | 31 | 42 | 0 | 90 | PM2.5 |
| November | 30 | 52 | 0 | 68 | PM2.5 |
| December | 31 | 56 | 0 | 80 | PM2.5 |
How 2025 compares
Among the 7 years EPA has published for the area (2019–2025), 2025 ranks 5th cleanest by days above AQI 100.
2025's median of 52 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 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.