# Cincinnati, OH Air Quality Index (AQI) Today > Source: https://breathecheck.com/air-quality/us/ohio/cincinnati/ > Live AQI for Cincinnati, OH with a plain verdict — go, short and unloaded, or don't go — plus the monitor behind it and our own hourly record. # Cincinnati, OH Air Quality Index (AQI) Today Readings collected automatically every hour; text written and checked by BreatheCheck Editorial . How this page is made → Right now: Cincinnati is at 37 , good . ## Is the air safe to breathe in Cincinnati today? In Cincinnati, BreatheCheck reads 37 as Go . The cutoffs: go below 101 , keep it short and easy from 101 to 150 , move it indoors above 150 . These are our own thresholds, drawn on the EPA bands — EPA itself classifies 101–150 as Unhealthy for Sensitive Groups and does not tell you how long to stay out. Go AQI 0–100 Normal outdoor plans. No change needed. Short & unloaded AQI 101–150 A 20-minute dog walk, not a 2.5-hour run. Keep it brief and easy. Don’t go AQI 151+ Move it indoors. Above 200 that becomes everyone, not just sensitive groups. Above 200 this stops being a personal call: everyone indoors. Duration and intensity are two separate dials | Under 20 min | 20–60 min | Over an hour | | Easy | Go | Go | Go | | Moderate | Go | Go | Go | | Hard | Go | Go | Go | Go Every combination lands the same way at this reading — a hard hour is no different from an easy twenty minutes. The two dials separate above 80 . Where people actually draw the line **All the thresholds people reported, and who reported them** - 60 Asthmatic runner one runner’s own 156-run log - 75–100 Daycare / school parents and staff in one r/toddlers thread, Aug 2025 — not a published rule - 100 Parent community-reported, escalating at 150 and 200 - 110 Runner community-reported EPA classifies 101–150 as Unhealthy for Sensitive Groups. That is an attributed classification, not a verdict on your lungs specifically. If you’re staying in, filter the room you’re actually in A portable HEPA unit or a Corsi-Rosenthal box — one builder put theirs at about $130 for a 12×14 bedroom. We don’t default to a MERV-13 swap in whole-house HVAC: it can restrict airflow, and the safe version needs a static-pressure check first. Dominant pollutant O3 UV index 0.8 low · modelled UV hour by hour in Cincinnati → Days above AQI 100 0 of 30 days we have recorded The record, day by day → ### Freight in the trench, cleaner air on the ridge Relief is what separates Cincinnati’s air from a flat city’s. The Ohio River runs at the bottom of the bowl, the hills stand several hundred feet above the water, and the Mill Creek valley cuts north from downtown as a second, narrower trench. Two neighborhoods a mile apart, one on a hilltop and one on the valley floor, are not breathing the same air on a still night, because the cold layer that forms in the low ground never reaches the ridge. What collects down in that trench is largely combustion. I-75 carries the region’s freight up the Mill Creek corridor, where a University of Cincinnati air pollution study measured roughly 159,000 vehicles a day past its sites with about 11 percent of them diesel. Add the Queensgate rail yard, barge traffic on the river, and the sulfate the wider Ohio Valley airshed has long carried from coal burned upwind, much reduced from its peak but not gone. Winter stagnation and midsummer regional haze are the two worst stretches, and they arrive by different routes. One citywide figure averages the ridge and the trench into a single number, which is why a local nonprofit, Groundwork Ohio River Valley, built a neighborhood-level monitoring dashboard rather than work from the official one. ## Where this number sits Of the 121 US metros reporting to us right now, Cincinnati is number 72 and number 2 of the 3 we track in Ohio. The pollutant driving it today is O3 . Nearby metros we also measure, and what they read at the same hour: - Lexington, KY — 79 miles away, AQI 35 - Louisville, KY — 91 miles away, AQI 44 - Indianapolis, IN — 99 miles away, AQI 35 - Columbus, OH — 99 miles away, AQI 34 Why a metro a short drive away reads differently → Where this reading comes from AirNow’s Cincinnati reporting area, about 1.9 miles from the metro centre. ## What has air quality in Cincinnati actually been? Daily maximum, our own readings. 30 days since 2026-08-16; nothing back-filled. Why we keep our own → 0 of the 30 days we have recorded so far went above AQI 100. | Date | Daily max AQI | EPA band | Hours read | | 2026-09-14 | 53 | Moderate | 22 | | 2026-09-13 | 65 | Moderate | 23 | | 2026-09-12 | 53 | Moderate | 23 | | 2026-09-11 | 55 | Moderate | 23 | | 2026-09-10 | 62 | Moderate | 23 | | 2026-09-09 | 64 | Moderate | 22 | | 2026-09-08 | 62 | Moderate | 23 | | 2026-09-07 | 55 | Moderate | 23 | | 2026-09-06 | 55 | Moderate | 23 | | 2026-09-05 | 59 | Moderate | 23 | | 2026-09-04 | 74 | Moderate | 23 | | 2026-09-03 | 73 | Moderate | 24 | | 2026-09-02 | 71 | Moderate | 23 | | 2026-09-01 | 71 | Moderate | 23 | | 2026-08-31 | 74 | Moderate | 23 | | 2026-08-30 | 67 | Moderate | 23 | | 2026-08-29 | 64 | Moderate | 23 | | 2026-08-28 | 59 | Moderate | 22 | | 2026-08-27 | 62 | Moderate | 23 | | 2026-08-26 | 100 | Moderate | 23 | | 2026-08-25 | 80 | Moderate | 23 | | 2026-08-24 | 72 | Moderate | 24 | | 2026-08-23 | 56 | Moderate | 23 | | 2026-08-22 | 60 | Moderate | 23 | | 2026-08-21 | 58 | Moderate | 23 | | 2026-08-20 | 62 | Moderate | 23 | | 2026-08-19 | 64 | Moderate | 23 | | 2026-08-18 | 52 | Moderate | 23 | | 2026-08-17 | 55 | Moderate | 26 | | 2026-08-16 | 67 | Moderate | 6 — partial day | ## Questions about Cincinnati **What is the air quality in Cincinnati right now?** AQI 37 — Good. That is number 72 of the 121 US metros reporting to us at this hour. **Which monitor does this number come from?** Cincinnati, about 1.9 miles from the metro centre. One instrument reports for the whole metro, so the side farthest from it is the least well described. **How does Cincinnati compare with metros nearby?** At this hour: Lexington 35, Louisville 44, Indianapolis 35, Columbus 34. Readings that close together suggest one airshed rather than local sources. **Does this include pollen?** No. The AQI covers PM2.5 , PM10 , ozone, NO₂, SO₂ and CO. A high-pollen day can read clean here and still put someone in bed. What the number means, band by band → · UV in Cincinnati → · Why apps disagree → ## Put this number in context On this page Alert me when Cincinnati turns One email when it crosses your threshold. Updated 14 Sep 2026, 22:12 UTC