Air Quality in Cincinnati, Ohio — Live
Live readings from PurpleAir sensors across Cincinnati — with free alerts the moment smoke drifts in.
AQI 34 from 5 PurpleAir sensors · Trending up · data from PurpleAir
As of , the air quality in Cincinnati, Ohio is AQI 34 — Good and rising — with PM2.5 at 6.2 µg/m³, the median of 5 live PurpleAir sensors reading 29 to 39. Canairy's verdict: Breathe easy.
For scale, that PM2.5 reading is below the World Health Organization's 24-hour guideline of 15 µg/m³. The WHO figure is a daily average and this is a live reading, so read it as a sense of magnitude rather than a formal exceedance — a brief spike and a bad day are not the same thing. More on the WHO guidelines
Pollen today in Cincinnati: weeds pollen is the strongest of the three at a high level, from Google's pollen forecast. Canairy shows the tree, grass and weed forecast beside the air reading on every plan, including the free one.
Free to download · Live data from PurpleAir & public monitors
Live PurpleAir sensor map for Cincinnati and Covington, Norwood, Newport, Blue Ash. Every dot is a real sensor, color-coded by current air quality.
Sensor by sensor in Cincinnati
The sensors Canairy reads in Cincinnati agree right now — all 5 sit in the Good band, a 10-point spread — so the city-wide number is a fair description of the whole area today.
| From city center | AQI | Category |
|---|---|---|
| 1.2 mi NNW | 37 | Good |
| 1.5 mi SSW | 31 | Good |
| 4.5 mi NNW | 34 | Good |
| 5.6 mi E | 39 | Good |
| 5.6 mi NE | 29 | Good |
Cincinnati has a real, well-documented air problem that has nothing to do with any single bad day. The metro sits in the Ohio River valley, where the basin's topography traps pollutants instead of letting them blow through, and the region consistently lands near the top of the American Lung Association's worst-cities list for year-round particle pollution. Add the Canadian wildfire smoke that has drifted down in recent summers and the picture is a city that has to watch its air more closely than most.
What Canairy does for Cincinnati
A clear verdict
Not just a number — a plain-English call for Cincinnati: open the windows, or keep them shut.
Smoke alerts
A push or text the moment the air crosses your threshold — and again when it clears.
A heads-up before it's bad
Trend alerts catch the air turning, so you can close up the house before the smoke settles in.
Every place you care about
Home, work, the kids' school — across Cincinnati or across the country, on one screen.
What the air in Cincinnati is doing next
| When | AQI | Expected air quality | Main pollutant |
|---|---|---|---|
| Today | 60 | Moderate | PM2.5 |
| Tomorrow | 50 | Good | PM2.5 |
| Monday | 57 | Moderate | PM2.5 |
| Tuesday | 75 | Moderate | ozone |
Forecast from EPA AirNow for the Cincinnati reporting area. Canairy watches the live sensors against it and tells you when the air actually crosses your threshold, rather than leaving you to check.
The Ohio River valley traps the air Cincinnati makes
Cincinnati grew up in a basin. The city and its inner neighborhoods sit low along the Ohio River and the Mill Creek valley, and that bowl-shaped geography does the city no favors on still, warm days. As an environmental epidemiologist working with the city put it, the valley topography often traps pollutants and prevents them from dispersing, so exhaust and industrial emissions that would scatter elsewhere tend to settle and build up here instead.
The numbers reflect it. In the American Lung Association's 2025 State of the Air report, which grades three years of monitoring data, the Cincinnati metro ranked 14th worst in the country for year-round particle pollution and earned an F for both ground-level ozone and short-term particle spikes. That is not a wildfire artifact. It is the everyday baseline of a valley city that still carries a heavy industrial and traffic load.
The Mill Creek valley and the I-75/I-71 corridor carry the worst of it
Not every Cincinnati neighborhood breathes the same air. The Mill Creek corridor, the long valley that runs up through the middle of Hamilton County from the Ohio River, was the industrial powerhouse of southwestern Ohio, and the legacy shows. Neighborhoods like Camp Washington, wedged between highways and old industry, face extreme exposure to pollution from traffic and factories, and they tend to have the least tree cover to buffer it.
The interstates make it worse. The I-75 and I-71 corridors funnel heavy diesel and commuter traffic straight through the basin, and when the city rolled out its Cincy Air Watch project it placed dozens of the 37 new PurpleAir monitors in exactly these high-asthma neighborhoods along the highways and the Mill Creek valley. If you live near one of those corridors, the reading a few blocks away can look very different from the citywide average.
Wildfire smoke now reaches Cincinnati too
For a long time Cincinnati's air story was about local sources, but that changed in the summer of 2023. When Canadian wildfires burned through their worst season on record, the smoke rode the jet stream south into the Ohio Valley. The Southwest Ohio Air Quality Agency issued an air quality alert for June 28 and 29, 2023, with both PM2.5 and ozone pushed into the unhealthy range, and it was the second such smoke episode in barely three weeks.
Those days behave differently from an ordinary bad-air day. The particle pollution arrives from hundreds of miles away, can spike fast, and does not care which neighborhood you live in. Health officials told residents, especially children, older adults, and anyone with asthma or heart conditions, to cut back on outdoor activity, run air conditioning on recirculate, and keep windows closed until the smoke cleared. It is exactly the kind of shift that is easy to miss if you are only glancing at the sky.
Cincinnati air quality FAQ
What is the air quality in Cincinnati right now?
As of September 5, 2026 at 5:37 PM EDT, the air quality in Cincinnati, Ohio is AQI 34 — Good — with PM2.5 at 6.2 µg/m³, the median of 5 live PurpleAir sensors. Open the windows. Great for outdoor activity.
Why does Cincinnati's air quality rank so poorly?
Two things stack up. Cincinnati sits in the Ohio River basin, and the valley topography traps pollutants instead of letting them disperse, so emissions from traffic and industry build up on still days. On top of that the metro still carries a heavy load of highway and industrial pollution, which is why the American Lung Association's 2025 State of the Air report ranked it 14th worst in the country for year-round particle pollution and gave it failing grades for ozone and short-term particle spikes.
Which Cincinnati neighborhoods have the worst air?
The neighborhoods along the Mill Creek valley and the I-75 and I-71 corridors tend to carry the most pollution, from heavy diesel traffic and the area's industrial legacy. Camp Washington, boxed in by highways and old industry, is one of the most exposed. When the city set up its Cincy Air Watch monitoring project it placed many of its sensors in exactly these high-asthma neighborhoods, so the reading near a corridor can be well above the citywide average.
What the AQI numbers mean
| AQI | Category | What it means for you |
|---|---|---|
| 0–50 | Good | Open the windows. Great for outdoor activity. |
| 51–100 | Moderate | Sensitive groups may want to take it slower outside. |
| 101–150 | Unhealthy for Sensitive Groups | Kids, elderly, and respiratory conditions stay closer to home. |
| 151–200 | Unhealthy | Skip outdoor exercise. Close windows. |
| 201–300 | Very Unhealthy | Limit time outside. N95 if you must go. |
| 301+ | Hazardous | Health emergency. Stay inside, run filtration if you have it. |
Canairy lets you tighten these bands if you’re more sensitive than the EPA default, so an alert can fire before the official category changes. How to read the Air Quality Index
Where these readings come from
The AQI at the top of this page is the median of the 5 curated PurpleAir sensors Canairy tracks in and around Cincinnati, with outliers set aside so that one sensor brought indoors — or parked beside a barbecue — cannot set the number for a whole city. Every sensor behind it is listed above with its distance and bearing from the city center. There is no black box here.
In the app, a place you save resolves the same way first. When no neighborhood sensor is reporting it falls back to the nearest EPA AirNow monitor, and anything modeled rather than measured is labelled a regional estimate rather than passed off as a sensor reading. How low-cost sensors compare to regulatory monitors
About Canairy
Canairy is free to download. The free plan covers one saved place with live readings, a plain-English verdict, and push alerts when the air crosses a threshold you choose. Paid plans add more places, faster refreshes, and SMS alerts. It is built by two parents in Sonoma County, California, who got tired of guessing whether it was safe to send the kids outside. Why we built it
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Air quality near Cincinnati
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