# Detroit, MI Air Quality Index (AQI) Today > Source: https://breathecheck.com/air-quality/us/michigan/detroit/ > Live AQI for Detroit, MI with a plain verdict — go, short and unloaded, or don't go — plus the monitor behind it and our own hourly record. # Detroit, MI Air Quality Index (AQI) Today Readings collected automatically every hour; text written and checked by BreatheCheck Editorial . How this page is made → Right now: Detroit is at 40 , good . ## Is the air safe to breathe in Detroit today? In Detroit, BreatheCheck reads 40 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 0.6 low · modelled UV hour by hour in Detroit → Days above AQI 100 2 of 30 days we have recorded The record, day by day → ### A line drawn through Wayne County When EPA designated this area nonattainment for sulfur dioxide in 2013, it did not draw the boundary around the metro. The north edge followed Michigan Avenue and then Woodward out to the Ontario border, the west edge ran down I-94 and I-75, and the south edge was the Monroe County line — a strip of Wayne County along the river, with most of the metro outside it. The sources sit inside that strip. Marathon’s refinery on Fort Street, rated near 140,000 barrels a day, is in it. So is the 48217 ZIP code, long described as the most polluted in Michigan, along with well over a hundred permitted emitting sites across southwest Detroit. The Ambassador Bridge, which carries more of the US-Canada merchandise trade by value than any other crossing, moves upward of 10,000 commercial vehicles on a typical weekday through the same few neighborhoods. Terrain redistributes none of it. This is flat lake plain around 600 feet between Lake St. Clair and Lake Erie, with no basin to pool cold air overnight and no ridge to stop a plume, so wind direction on the day decides which neighborhood gets the worst of it. The regulatory chapter closed in April 2026, when the area was redesignated to attainment for that sulfur dioxide standard. The stacks, the bridge and the truck lanes stayed where they were. ## Where this number sits Of the 121 US metros reporting to us right now, Detroit is number 62 and the highest of the 2 we track in Michigan. The pollutant driving it today is O3 . Nearby metros we also measure, and what they read at the same hour: - Cleveland, OH — 90 miles away, AQI 37 - Fort Wayne, IN — 136 miles away, AQI 31 - Grand Rapids, MI — 140 miles away, AQI 38 - Columbus, OH — 164 miles away, AQI 34 Why a metro a short drive away reads differently → Where this reading comes from AirNow’s Southeast reporting area, about 19.8 miles from the metro centre. ## What has air quality in Detroit actually been? Daily maximum, our own readings. 30 days since 2026-08-16; nothing back-filled. Why we keep our own → 2 of the 30 days we have recorded so far went above AQI 100. | Date | Daily max AQI | EPA band | Hours read | | 2026-09-14 | 42 | Good | 22 | | 2026-09-13 | 59 | Moderate | 23 | | 2026-09-12 | 52 | Moderate | 23 | | 2026-09-11 | 60 | Moderate | 23 | | 2026-09-10 | 52 | Moderate | 23 | | 2026-09-09 | 61 | Moderate | 23 | | 2026-09-08 | 71 | Moderate | 23 | | 2026-09-07 | 52 | Moderate | 23 | | 2026-09-06 | 39 | Good | 23 | | 2026-09-05 | 55 | Moderate | 23 | | 2026-09-04 | 56 | Moderate | 23 | | 2026-09-03 | 63 | Moderate | 24 | | 2026-09-02 | 108 | Unhealthy for Sensitive Groups | 23 | | 2026-09-01 | 147 | Unhealthy for Sensitive Groups | 23 | | 2026-08-31 | 73 | Moderate | 23 | | 2026-08-30 | 57 | Moderate | 23 | | 2026-08-29 | 62 | Moderate | 23 | | 2026-08-28 | 59 | Moderate | 22 | | 2026-08-27 | 61 | Moderate | 23 | | 2026-08-26 | 71 | Moderate | 23 | | 2026-08-25 | 53 | Moderate | 23 | | 2026-08-24 | 69 | Moderate | 24 | | 2026-08-23 | 73 | Moderate | 23 | | 2026-08-22 | 61 | Moderate | 23 | | 2026-08-21 | 79 | Moderate | 23 | | 2026-08-20 | 59 | Moderate | 23 | | 2026-08-19 | 46 | Good | 23 | | 2026-08-18 | 55 | Moderate | 23 | | 2026-08-17 | 42 | Good | 26 | | 2026-08-16 | 56 | Moderate | 7 — partial day | ## Questions about Detroit **What is the air quality in Detroit right now?** AQI 40 — Good. That is number 62 of the 121 US metros reporting to us at this hour. **Which monitor does this number come from?** Southeast, about 19.8 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 Detroit compare with metros nearby?** At this hour: Cleveland 37, Fort Wayne 31, Grand Rapids 38, 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 Detroit → · Why apps disagree → ## Put this number in context On this page Alert me when Detroit turns One email when it crosses your threshold. Updated 14 Sep 2026, 22:12 UTC