Louisville Air Quality in March
Across 2019–2025, Louisville's March air quality had a median AQI of 52 (Moderate) over 217 monitored days in the Louisville/Jefferson County, KY-IN area. 0.0% of March days (0 of 217) reached Unhealthy for Sensitive Groups or worse, and fine particulate matter (PM2.5) set the daily AQI on 71.9% of days. The cleanest March on record here was 2024 (median AQI 47, 0 days above 100) and the worst was 2021 (median 55, 0 days above 100, peak AQI 79).
- Good: 42.4%
- Moderate: 57.6%
- Unhealthy for Sensitive Groups: 0.0%
- Unhealthy or worse: 0.0%
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.
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How is the air in Louisville in March?
Moderate on a typical day: median AQI 52 across 2019–2025, with 0.0% of March days above AQI 100. Fine particulate matter (PM2.5) is the main driver.
- ✓42.4% of March days were Good (AQI 0–50), 57.6% Moderate (51–100).
- ✓0 days of 217 reached AQI 101+; the March peak was 91.
- ✓Best March: 2024; worst March: 2021.
Frequently asked questions
What is the air quality like in Louisville in March?▾
Across 2019–2025, the median daily AQI in Louisville in March was 52 (Moderate). 42.4% of days were Good, 57.6% Moderate, and 0.0% reached Unhealthy for Sensitive Groups or worse, based on 217 monitored days in EPA's Air Quality System.
Is March a good time for outdoor exercise in Louisville?▾
A typical March day in Louisville is Moderate (median AQI 52): outdoor exercise is acceptable for most people, but unusually sensitive individuals should watch for symptoms, and fewer than 1% of March days reached AQI 101+ — the level at which EPA advises people with asthma, children and older adults to shorten hard outdoor exertion.
Which pollutant causes Louisville's March air quality problems?▾
Fine particulate matter (PM2.5) set the daily AQI on 71.9% of March days in Louisville. The highest March AQI recorded in 2019–2025 was 91 (Moderate), in 2021.
Louisville March air quality, year by year
Louisville March air quality by year (Louisville/Jefferson County, KY-IN, EPA AQS daily AQI)
| Year | Days monitored | Median AQI | Days above 100 | Peak AQI | Main pollutant |
|---|---|---|---|---|---|
| 2019 | 31 | 55 | 0 | 78 | PM2.5 |
| 2020 | 31 | 52 | 0 | 67 | PM2.5 |
| 2021worst | 31 | 55 | 0 | 79 | PM2.5 |
| 2022 | 31 | 52 | 0 | 80 | PM2.5 |
| 2023 | 31 | 54 | 0 | 91 | PM2.5 |
| 2024cleanest | 31 | 47 | 0 | 61 | PM2.5 |
| 2025 | 31 | 52 | 0 | 77 | PM2.5 |
What March air means in Louisville
A typical March day in Louisville is Moderate (median AQI 52): outdoor exercise is acceptable for most people, but unusually sensitive individuals should watch for symptoms, and fewer than 1% of March days reached AQI 101+ — the level at which EPA advises people with asthma, children and older adults to shorten hard outdoor exertion.
March's median AQI of 52 is in line with Louisville's whole-year median of 54, so this period is neither a clean nor a dirty stretch for the area. Nationally, the median March AQI across every EPA metro area (102,455 metro-days, 2019–2025) is 42, so Louisville runs above the national March norm; 0.0% of its March days topped AQI 100 versus 0.4% nationally (about the same).
March is part of Louisville's spring season (March, April, May); the spring page pools all three months.
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 month 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.