Millions of people across parts of Ohio, Kentucky, and Indiana have been warned to limit driving and reduce outdoor pollution as air quality levels deteriorate due to rising ozone pollution.
The National Weather Service (NWS) has issued Air Quality Alerts covering a wide swath of the region — including the Miami Valley in Ohio and the greater Cincinnati area spanning three states — with warnings in place until midnight on Thursday.
Where the Air Quality Alerts Are in Place
The warnings affect multiple counties and major cities, including:
- Ohio (Miami Valley): Montgomery (Dayton), Clark (Springfield), Greene, Miami, Darke, Preble, and Shelby counties
- Southwest Ohio: Butler, Hamilton (Cincinnati), Clermont, and Warren counties
- Northern Kentucky: Boone, Kenton, and Campbell counties
- Southeast Indiana: Dearborn County
In total, the alert spans densely populated communities across the tri-state region, including Dayton and Cincinnati, placing millions under advisory conditions.
Why Air Quality Is Getting Worse
The culprit is ground-level ozone, a key ingredient in smog that forms when pollution from sources like car exhaust reacts with sunlight.
Unlike pollutants directly released into the air, ozone is created through a chemical reaction between nitrogen oxides and volatile organic compounds (which are basically emissions produced by vehicles, power plants, and industrial activity) under hot, sunny conditions…