Air Quality in Louisville, Kentucky — Live

Live readings from PurpleAir sensors across Louisville — with free alerts when ozone action days or west Louisville air toxics spike.

Live Louisville AQI from nearby PurpleAir sensors loads when this page opens in a browser, along with a live sensor map covering Louisville and St. Matthews, Shepherdsville, New Albany, IN, Jeffersonville, IN.

Louisville's air isn't a wildfire-smoke story the way it is out West — most winters and springs the readings are unremarkable. What defines it instead is a stubborn ozone problem every summer and one of the country's most studied environmental-justice fights over industrial air: the Rubbertown corridor on the city's west side, where eleven chemical plants have shaped a neighborhood's air for generations. Add in the region's June-through-September Ozone Action Days and the thick, hazy stillness that Ohio Valley humidity produces most summer afternoons, and Louisville's air quality is a real year-round variable — just not a fire-driven one.

Canairy watches the sensors around your home, your kids' school, and everywhere else you care about, and tells you in plain English when the air changes enough to matter.

Rubbertown and the fight over west Louisville's air

Along the Ohio River on Louisville's west side sits Rubbertown, an industrial corridor of eleven chemical plants — synthetic rubber, solvent, and chemical manufacturers that trace back to a World War II buildup of wartime rubber production. A federal West Louisville Air Toxics Study, run with the University of Louisville from 2000 to 2005, found 17 hazardous air pollutants at levels high enough to justify action. In 2005 Louisville Metro responded with the Strategic Toxic Air Reduction (STAR) program, one of the strictest local air-toxics ordinances of its kind in the country, tightening emissions limits on Rubbertown's plants specifically.

The story hasn't stopped there. In 2024 the EPA and the University of Louisville's Envirome Institute launched the Rubbertown Air Toxics and Health Action (RATHA) project, a three-year, roughly $1 million effort to expand air monitoring and study health effects in neighborhoods like Shawnee that sit closest to the plants. Researchers pointed to elevated rates of liver, lung, and stomach cancer in Jefferson County, disproportionately among Black residents — echoing an older, well-documented case at a former B.F. Goodrich plant in Rubbertown, where vinyl chloride exposure caused rare liver cancers in workers decades ago. In 2025 the Trump EPA terminated the RATHA grant and rejected the district's appeal, leaving the expanded monitoring in limbo even as Rubbertown keeps operating.

Ozone Action Days run June through September

Louisville's other recurring problem is ground-level ozone, formed when summer heat and sunlight react with vehicle exhaust, industrial emissions, and vapors from everyday sources like printing shops, auto body shops, and lawn equipment. The Kentuckiana Ozone Prevention Coalition calls an Ozone Action Day whenever conditions favor that reaction, and Louisville Metro's Air Pollution Control District — using data from the regional KAIRE monitoring network — posts an updated Air Quality Index four times a day on weekdays specifically because ozone here is common enough to need routine tracking, not just occasional smoke-season vigilance.

The American Lung Association's 2025 State of the Air report gave Jefferson County an F for ozone, citing an average of 8.2 unhealthy ozone days a year — the 29th worst count in the country and second worst in its region — alongside a D grade for short-term particle pollution and a failing grade for year-round particle levels. Advocacy Director Shannon Baker put it plainly: too many people in Louisville live with unhealthy ozone, and it's causing kids to have asthma attacks and making people who work outdoors sick.

Why Louisville's summer sky turns hazy and white

On humid afternoons Louisville's sky can turn a milky white instead of blue, and WAVE 3 meteorologist Tawana Andrews explained why in a July 2026 interview with Louisville Public Media: once relative humidity climbs past 60 to 70 percent, water vapor starts merging with airborne particles — pollen, dust, and especially sulfate aerosols formed when industrial sulfur dioxide reacts with oxygen and moisture in the air. Those droplets scatter sunlight instead of letting it pass straight through, whitening the sky and turning sunsets a deeper red and orange.

Canadian wildfire smoke has become part of that same summer haze in recent years, drifting into the Ohio Valley without ever being the main event the way it is farther north. That's worth knowing because a hazy-looking sky over Louisville isn't automatically a health emergency — the sulfate haze itself isn't harmful at typical concentrations — but the ozone and particle levels underneath it can be, which is exactly why the number matters more than what the sky looks like.

Louisville air quality FAQ

What is the air quality in Louisville right now?

This page shows the current AQI for Louisville, calculated from PurpleAir sensors across the city and updated continuously. The map below shows every live sensor, so you can check the reading closest to your own neighborhood.

Why does west Louisville have worse air than the rest of the city?

West Louisville sits closest to Rubbertown, an industrial corridor of eleven chemical plants along the Ohio River. A 2000-2005 federal study found 17 hazardous air pollutants at elevated levels there, which led to Louisville's Strategic Toxic Air Reduction (STAR) program in 2005 and, more recently, an EPA-funded health study focused on neighborhoods like Shawnee.

Why does Louisville get so many Ozone Action Days in summer?

Ground-level ozone forms when sunlight and summer heat react with vehicle exhaust, industrial emissions, and everyday vapors from sources like auto body shops and lawn equipment. The Kentuckiana Ozone Prevention Coalition calls an Ozone Action Day whenever conditions are right for that reaction, common enough from June through September that the American Lung Association gave Jefferson County an F for ozone in its 2025 report.

What AQI level is unhealthy?

Under the US EPA scale, AQI 0-50 is Good and 51-100 is Moderate. From 101 the air is Unhealthy for Sensitive Groups - kids, older adults, and people with asthma or heart conditions - and above 150 it's Unhealthy for everyone. Canairy translates these numbers into a plain-English verdict, like whether to close the windows or move a workout indoors.

Where does Canairy's Louisville data come from?

Readings come from PurpleAir's network of laser particle sensors across Louisville and surrounding towns, cross-referenced with government monitors and the Google Air Quality API. You can see every sensor behind your numbers on the live map - there's no black box.

Is Canairy free?

Yes. The Canairy app is free to download and includes live air quality for all your saved places, plain-English verdicts, and free push alerts when the air crosses your threshold. A paid plan adds extras like SMS text alerts.

Get Canairy free on Google Play.