SmogRank / Episodes / United States
Ohio, United States, July 2026
For 1 day, on 1 July 2026, 24 cities in the United States had PM2.5 at least twice their usual for the time of year. The worst reading was Westerville, Ohio, United States: 31.8 µg/m³ on 1 July, about 3.1× its usual 10.3.
No cause named We have no fire or smoke records for these days, so we only say what the measurements show.
Cities reached 24 in 1 country
Days 1 1 July 2026
Worst day 1 July 24 cities counted
Furthest above usual 3.6× Mason
Day by day
Play 1 July 24 cities at twice their usual or more
Fort Wayne Muncie Anderson Toledo Kokomo Elkhart Fishers Ann Arbor White Oak Kalamazoo Ypsilanti Dublin South Bend Fort Thomas Indianapolis Taylor Gahanna Lincoln Park Dearborn Columbus Southfield Detroit Windsor Royal Oak Lafayette Eastpointe Flint Michigan City Holland Bloomington Portage Gary Chatham East Chicago Hammond Calumet City Port Huron Dolton Sarnia Terre Haute Akron Ashland Blue Island Chicago Shaker Heights Evergreen Park Oak Lawn Evanston Bridgeview Skokie Elmwood Park Brookfield Niles Jasper Franklin Park Park Ridge Des Plaines Painesville Joliet Zion Naperville Champaign Aurora South Milwaukee Elgin Cary Warren St. Thomas Youngstown London Steubenville Weirton Brookfield Weirton Heights Waukesha Hermitage Bloomington Decatur Oconomowoc Upper Saint Clair Rockford Pittsburgh Erie Wilkinsburg West Mifflin McKeesport Brantford Peoria Springfield Madison Middleton Hamilton Waterdown Redford Cleveland Wyoming Grand Rapids Oregon Canton Columbus Portsmouth Norwood Middletown Lansing Jenison Milwaukee Perrysburg Northbrook Springfield Cincinnati Dayton Westerville Lebanon Medina Lima Cleveland Heights Mason 28 Jun 29 30 1 Jul 2 3 4 Every measured city in the area, coloured by its PM2.5 that day; a dark ring marks a city at twice its usual or more. Bars: cities counted each day, coloured by their median level. Choose a day or press play; without JavaScript, the days link to that day's world ranking.
How it spread
Westerville Westerville, 28 June: 6.3 µg/m³, 0.6× usual Westerville, 29 June: 10.9 µg/m³, 1.1× usual Westerville, 30 June: 20.2 µg/m³, 2.0× usual Westerville, 1 July: 31.8 µg/m³, 3.1× usual Westerville, 2 July: 25.1 µg/m³, 2.4× usual Westerville, 3 July: 19.2 µg/m³, 1.9× usual Westerville, 4 July: 17.0 µg/m³, 1.7× usual Lima Lima, 28 June: 12.4 µg/m³, 1.3× usual Lima, 29 June: 15.2 µg/m³, 1.6× usual Lima, 30 June: 23.5 µg/m³, 2.4× usual Lima, 1 July: 30.9 µg/m³, 3.2× usual Lima, 2 July: 20.6 µg/m³, 2.1× usual Lima, 3 July: 17.0 µg/m³, 1.8× usual Lima, 4 July: 13.4 µg/m³, 1.4× usual Mason Mason, 28 June: 3.6 µg/m³, 0.4× usual Mason, 29 June: 13.5 µg/m³, 1.6× usual Mason, 30 June: 18.6 µg/m³, 2.2× usual Mason, 1 July: 30.5 µg/m³, 3.6× usual Mason, 2 July: 21.0 µg/m³, 2.5× usual Mason, 3 July: 16.0 µg/m³, 1.9× usual Mason, 4 July: 8.7 µg/m³, 1.0× usual Middletown Middletown, 28 June: 7.6 µg/m³, 0.7× usual Middletown, 29 June: 17.0 µg/m³, 1.5× usual Middletown, 30 June: 22.9 µg/m³, 2.0× usual Middletown, 1 July: 30.4 µg/m³, 2.7× usual Middletown, 2 July: 23.4 µg/m³, 2.1× usual Middletown, 3 July: 21.9 µg/m³, 1.9× usual Middletown, 4 July: 21.0 µg/m³, 1.9× usual Cincinnati Cincinnati, 28 June: 6.8 µg/m³, 0.6× usual Cincinnati, 29 June: 15.0 µg/m³, 1.4× usual Cincinnati, 30 June: 20.9 µg/m³, 2.0× usual Cincinnati, 1 July: 30.3 µg/m³, 2.9× usual Cincinnati, 2 July: 20.9 µg/m³, 2.0× usual Cincinnati, 3 July: 16.9 µg/m³, 1.6× usual Cincinnati, 4 July: 14.2 µg/m³, 1.3× usual Wyoming Wyoming, 28 June: 11.4 µg/m³, 1.0× usual Wyoming, 29 June: 13.7 µg/m³, 1.1× usual Wyoming, 30 June: 21.7 µg/m³, 1.8× usual Wyoming, 1 July: 30.3 µg/m³, 2.5× usual Wyoming, 2 July: 15.6 µg/m³, 1.3× usual Wyoming, 3 July: 12.3 µg/m³, 1.0× usual Wyoming, 4 July: no reading Norwood Norwood, 28 June: 7.0 µg/m³, 0.6× usual Norwood, 29 June: 16.6 µg/m³, 1.5× usual Norwood, 30 June: 21.7 µg/m³, 2.0× usual Norwood, 1 July: 29.5 µg/m³, 2.7× usual Norwood, 2 July: 22.4 µg/m³, 2.0× usual Norwood, 3 July: 19.9 µg/m³, 1.8× usual Norwood, 4 July: 13.7 µg/m³, 1.2× usual Dayton Dayton, 28 June: 4.8 µg/m³, 0.5× usual Dayton, 29 June: 13.9 µg/m³, 1.4× usual Dayton, 30 June: 20.6 µg/m³, 2.1× usual Dayton, 1 July: 29.3 µg/m³, 3.0× usual Dayton, 2 July: 20.5 µg/m³, 2.1× usual Dayton, 3 July: 14.7 µg/m³, 1.5× usual Dayton, 4 July: 16.0 µg/m³, 1.6× usual Perrysburg Perrysburg, 28 June: 10.4 µg/m³, 1.1× usual Perrysburg, 29 June: 11.5 µg/m³, 1.2× usual Perrysburg, 30 June: 21.3 µg/m³, 2.2× usual Perrysburg, 1 July: 28.6 µg/m³, 2.9× usual Perrysburg, 2 July: 20.8 µg/m³, 2.1× usual Perrysburg, 3 July: 14.2 µg/m³, 1.4× usual Perrysburg, 4 July: 12.7 µg/m³, 1.3× usual Springfield Springfield, 28 June: 5.7 µg/m³, 0.6× usual Springfield, 29 June: 13.0 µg/m³, 1.3× usual Springfield, 30 June: 18.6 µg/m³, 1.9× usual Springfield, 1 July: 28.0 µg/m³, 2.9× usual Springfield, 2 July: 20.2 µg/m³, 2.1× usual Springfield, 3 July: 15.1 µg/m³, 1.5× usual Springfield, 4 July: 20.0 µg/m³, 2.0× usual Oregon Oregon, 28 June: 7.1 µg/m³, 0.7× usual Oregon, 29 June: 9.4 µg/m³, 0.9× usual Oregon, 30 June: 21.1 µg/m³, 2.0× usual Oregon, 1 July: 27.6 µg/m³, 2.6× usual Oregon, 2 July: 21.6 µg/m³, 2.0× usual Oregon, 3 July: 14.6 µg/m³, 1.4× usual Oregon, 4 July: 9.6 µg/m³, 0.9× usual Medina Medina, 28 June: 9.6 µg/m³, 1.2× usual Medina, 29 June: 7.7 µg/m³, 0.9× usual Medina, 30 June: 14.5 µg/m³, 1.7× usual Medina, 1 July: 26.9 µg/m³, 3.2× usual Medina, 2 July: 19.3 µg/m³, 2.3× usual Medina, 3 July: 12.1 µg/m³, 1.5× usual Medina, 4 July: 9.3 µg/m³, 1.1× usual Cleveland Cleveland, 28 June: 9.3 µg/m³, 0.9× usual Cleveland, 29 June: 11.3 µg/m³, 1.1× usual Cleveland, 30 June: 15.9 µg/m³, 1.5× usual Cleveland, 1 July: 26.7 µg/m³, 2.5× usual Cleveland, 2 July: 19.5 µg/m³, 1.8× usual Cleveland, 3 July: 13.1 µg/m³, 1.2× usual Cleveland, 4 July: 13.4 µg/m³, 1.3× usual Northbrook Northbrook, 28 June: 9.3 µg/m³, 1.0× usual Northbrook, 29 June: 13.5 µg/m³, 1.5× usual Northbrook, 30 June: 24.5 µg/m³, 2.7× usual Northbrook, 1 July: 26.4 µg/m³, 2.9× usual Northbrook, 2 July: 11.6 µg/m³, 1.3× usual Northbrook, 3 July: 7.9 µg/m³, 0.9× usual Northbrook, 4 July: 9.0 µg/m³, 1.0× usual Columbus Columbus, 28 June: 4.5 µg/m³, 0.4× usual Columbus, 29 June: 8.6 µg/m³, 0.9× usual Columbus, 30 June: 14.9 µg/m³, 1.5× usual Columbus, 1 July: 26.4 µg/m³, 2.6× usual Columbus, 2 July: 22.0 µg/m³, 2.2× usual Columbus, 3 July: 15.5 µg/m³, 1.5× usual Columbus, 4 July: 12.9 µg/m³, 1.3× usual Canton Canton, 28 June: 9.5 µg/m³, 0.9× usual Canton, 29 June: 8.2 µg/m³, 0.8× usual Canton, 30 June: 15.7 µg/m³, 1.5× usual Canton, 1 July: 26.4 µg/m³, 2.6× usual Canton, 2 July: 22.3 µg/m³, 2.2× usual Canton, 3 July: 14.5 µg/m³, 1.4× usual Canton, 4 July: 12.1 µg/m³, 1.2× usual Redford Redford, 28 June: 6.6 µg/m³, 0.6× usual Redford, 29 June: 8.0 µg/m³, 0.7× usual Redford, 30 June: 15.1 µg/m³, 1.4× usual Redford, 1 July: 25.9 µg/m³, 2.4× usual Redford, 2 July: 13.8 µg/m³, 1.3× usual Redford, 3 July: 5.7 µg/m³, 0.5× usual Redford, 4 July: 26.4 µg/m³, 2.4× usual Cleveland Heights Cleveland Heights, 28 June: 7.6 µg/m³, 1.0× usual Cleveland Heights, 29 June: 8.8 µg/m³, 1.2× usual Cleveland Heights, 30 June: 14.5 µg/m³, 1.9× usual Cleveland Heights, 1 July: 25.5 µg/m³, 3.4× usual Cleveland Heights, 2 July: 17.9 µg/m³, 2.4× usual Cleveland Heights, 3 July: 13.6 µg/m³, 1.8× usual Cleveland Heights, 4 July: 19.1 µg/m³, 2.5× usual Lebanon Lebanon, 28 June: 2.9 µg/m³, 0.4× usual Lebanon, 29 June: 11.1 µg/m³, 1.4× usual Lebanon, 30 June: 16.8 µg/m³, 2.1× usual Lebanon, 1 July: 25.5 µg/m³, 3.1× usual Lebanon, 2 July: 17.8 µg/m³, 2.2× usual Lebanon, 3 July: 15.7 µg/m³, 1.9× usual Lebanon, 4 July: 14.4 µg/m³, 1.8× usual Milwaukee Milwaukee, 28 June: 9.2 µg/m³, 1.0× usual Milwaukee, 29 June: 10.4 µg/m³, 1.2× usual Milwaukee, 30 June: 19.1 µg/m³, 2.2× usual Milwaukee, 1 July: 25.3 µg/m³, 2.9× usual Milwaukee, 2 July: 6.6 µg/m³, 0.7× usual Milwaukee, 3 July: 6.9 µg/m³, 0.8× usual Milwaukee, 4 July: 11.7 µg/m³, 1.3× usual Lansing Lansing, 28 June: 8.3 µg/m³, 0.9× usual Lansing, 29 June: 8.8 µg/m³, 1.0× usual Lansing, 30 June: 16.8 µg/m³, 1.9× usual Lansing, 1 July: 25.2 µg/m³, 2.8× usual Lansing, 2 July: 14.0 µg/m³, 1.6× usual Lansing, 3 July: 7.2 µg/m³, 0.8× usual Lansing, 4 July: 9.1 µg/m³, 1.0× usual Portsmouth Portsmouth, 28 June: 6.9 µg/m³, 0.8× usual Portsmouth, 29 June: 10.5 µg/m³, 1.1× usual Portsmouth, 30 June: 16.9 µg/m³, 1.8× usual Portsmouth, 1 July: 25.2 µg/m³, 2.7× usual Portsmouth, 2 July: 23.9 µg/m³, 2.6× usual Portsmouth, 3 July: 20.6 µg/m³, 2.2× usual Portsmouth, 4 July: 16.8 µg/m³, 1.8× usual Grand Rapids Grand Rapids, 28 June: 7.2 µg/m³, 0.7× usual Grand Rapids, 29 June: 9.7 µg/m³, 1.0× usual Grand Rapids, 30 June: 18.4 µg/m³, 1.9× usual Grand Rapids, 1 July: 25.1 µg/m³, 2.5× usual Grand Rapids, 2 July: 10.1 µg/m³, 1.0× usual Grand Rapids, 3 July: 7.3 µg/m³, 0.7× usual Grand Rapids, 4 July: 12.0 µg/m³, 1.2× usual Jenison Jenison, 28 June: 6.8 µg/m³, 0.8× usual Jenison, 29 June: 9.8 µg/m³, 1.1× usual Jenison, 30 June: 18.3 µg/m³, 2.1× usual Jenison, 1 July: 25.0 µg/m³, 2.8× usual Jenison, 2 July: 10.4 µg/m³, 1.2× usual Jenison, 3 July: 6.9 µg/m³, 0.8× usual Jenison, 4 July: 12.7 µg/m³, 1.4× usual 28 Jun 29 30 1 Jul 2 3 4 Every counted city, in the order the episode reached them, 3 days before to 3 after. Each square is a day, coloured by that day's PM2.5; outlined: at twice the city's usual or more. Good 0–50
Moderate 51–100
Sensitive groups 101–150
Unhealthy 151–200
Very unhealthy 201–300
Hazardous 301+
Every city it reached
City Days Highest Usual Above usual
Mason Ohio, United States 1 1 July 8.4 3.6× Cleveland Heights Ohio, United States 1 1 July 7.5 3.4× Medina Ohio, United States 1 1 July 8.3 3.2× Lima Ohio, United States 1 1 July 9.7 3.2× Lebanon Ohio, United States 1 1 July 8.1 3.1× Westerville Ohio, United States 1 1 July 10.3 3.1× Dayton Ohio, United States 1 1 July 9.8 3.0× Northbrook Illinois, United States 1 1 July 9.0 2.9× Perrysburg Ohio, United States 1 1 July 9.9 2.9× Milwaukee Wisconsin, United States 1 1 July 8.8 2.9× Cincinnati Ohio, United States 1 1 July 10.6 2.9× Springfield Ohio, United States 1 1 July 9.8 2.9× Jenison Michigan, United States 1 1 July 8.8 2.8× Lansing Michigan, United States 1 1 July 8.9 2.8× Portsmouth Ohio, United States 1 1 July 9.2 2.7× Middletown Ohio, United States 1 1 July 11.3 2.7× Norwood Ohio, United States 1 1 July 11.0 2.7× Columbus Ohio, United States 1 1 July 10.1 2.6× Oregon Ohio, United States 1 1 July 10.6 2.6× Canton Ohio, United States 1 1 July 10.3 2.6× Grand Rapids Michigan, United States 1 1 July 9.9 2.5× Wyoming Michigan, United States 1 1 July 12.0 2.5× Cleveland Ohio, United States 1 1 July 10.6 2.5× Redford Michigan, United States 1 4 July 10.9 2.4×
Daily means in µg/m³. Usual: the city's median for this time of year (its days within 21 days of the date, every year, leaving out the week around it). Above usual: its highest day against that.
Against other episodes in the United States
Number 34 of 98 episodes in the United States since our records began, by cities reached.
North-eastern United States and Canada, June and July 2023 279 North-eastern United States and Canada, July 2026 264 North-eastern United States and Canada, May and June 2023 260 North-eastern United States and Canada, July and August 2025 241 North-eastern United States and Canada, July 2023 241 North-eastern United States and Canada, June 2025 196 North-eastern United States and Canada, June 2023 161 North-eastern United States and Canada, July 2025 119 North-western United States and Canada, August 2023 110 North-eastern United States, June 2025 104 North-western United States and Canada, August 2026 99 North-eastern United States and Canada, February 2026 96 Ohio, United States, July 2026 24 Bars: cities reached; colour: the level of the episode's highest daily reading. All 98 .
Use this page SmogRank, Ohio, United States, July 2026: 24 cities with PM2.5 at twice their usual or more, 1 July 2026, smogrank.com/episodes/2026-07-ohio-united-states (accessed 2 October 2026).
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You're welcome to reuse a single chart, image or figure with this citation and a link. Terms .
An episode is a run of days when many cities close to each other (four or more within 350 km on a day, 8 or more in all) each had a daily PM2.5 mean of at least 25 µg/m³ and at least 2 times their usual for that time of year. Found in our own measurements, not picked by hand. How we find episodes . Values are each city's daily mean of its own monitors; causes are the usual kinds for a pattern like this, not a confirmed source.
