# Ohio air quality today — live AQI by metro > Source: https://breathecheck.com/air-quality/us/ohio/ > Live AQI for 3 Ohio metros, updated hourly from EPA AirNow. Where the state's air is worst right now, and how far apart its cities are. # Ohio air quality today Updated 14 Sep 2026, 22:12 UTC · LIVE 3 metros tracked Across the 3 Ohio metros BreatheCheck measures, air is worst right now in Cleveland at AQI 37 (Good) and cleanest in Columbus at AQI 34 . ## Which Ohio city has the worst air quality right now? | # | Metro | AQI | UV now | Dominant | | 1 | Cleveland | 37 Good | 0.5 | O3 | | 2 | Cincinnati | 37 Good | 0.8 | O3 | | 3 | Columbus | 34 Good | 0.7 | O3 | ## What is the UV index in Ohio today? The strongest UV in Ohio today is 6.7 (High) in Cincinnati, arriving around 1pm local time. The mildest of the 3 metros we model here peaks at 5.5 in Cleveland. UV is modelled, not measured — unlike the AQI above it, which comes off an instrument. Hour by hour in Cincinnati → ## Local agencies monitor, a river valley traps Which office watches the air in an Ohio county depends on the county. Ohio EPA’s Division of Air Pollution Control contracts the work out to local agencies: the Regional Air Pollution Control Agency, run out of Public Health in Dayton and Montgomery County, covers Clark, Darke, Greene, Miami, Montgomery and Preble; the Southwest Ohio Air Quality Agency, a division of Hamilton County’s environmental services department, covers Butler, Clermont, Clinton, Hamilton and Warren; the Portsmouth local air agency, housed in a city health department, covers Adams, Brown, Highland, Lawrence and Scioto. Toledo and Lake County run their own. One state number is assembled from a patchwork of offices. The Cleveland area’s ozone record shows how far that number can move. Cuyahoga, Geauga, Lake, Lorain, Medina, Portage and Summit were designated marginal nonattainment for the 2015 ozone standard in June 2018, reclassified twice as attainment deadlines passed — to serious by operation of law in December 2024 — and then redesignated to attainment in 2026. The Ohio portion of the Cincinnati area, meaning Butler, Clermont, Hamilton and Warren counties, made the same return in June 2022. Cincinnati’s other pollutant is more persistent. The American Lung Association’s 2025 report placed the metro fourteenth worst nationally for year-round particle pollution, and the Ohio River runs there in a valley cut below the surrounding plateau, which holds cool air on calm nights. Ozone on the Erie shore in July and particulate in a river valley in January are two different problems reported on one index. ## Where do these Ohio readings come from? 3 of the 3 metros here report from a named regulatory monitor — Columbus, Cleveland-Akron-Lorain, Cincinnati. The dominant pollutant across Ohio today is O3 . We track 3 metropolitan areas in Ohio, not the whole state, and 3 of them have a page of its own. There is no state-wide average here on purpose: averaging 3 metros into one figure would invent a value for all the ground between them. How we measure, and what we refuse to estimate → ## Neighbouring states Smoke and inversions do not stop at a state line, so when Ohio looks wrong the answer is often next door. ## Related Updated 14 Sep 2026, 22:12 UTC