# Michigan air quality today — live AQI by metro > Source: https://breathecheck.com/air-quality/us/michigan/ > Live AQI for 2 Michigan metros, updated hourly from EPA AirNow. Where the state's air is worst right now, and how far apart its cities are. # Michigan air quality today Updated 14 Sep 2026, 22:12 UTC · LIVE 2 metros tracked Across the 2 Michigan metros BreatheCheck measures, air is worst right now in Detroit at AQI 40 (Good) and cleanest in Grand Rapids at AQI 38 . ## Which Michigan city has the worst air quality right now? | # | Metro | AQI | UV now | Dominant | | 1 | Detroit | 40 Good | 0.6 | O3 | | 2 | Grand Rapids no page yet | 38 Good | 0.6 | — | ## What is the UV index in Michigan today? The strongest UV in Michigan today is 5.7 (High) in Detroit, arriving around 1pm local time. The mildest of the 2 metros we model here peaks at 5.7 in Grand Rapids. UV is modelled, not measured — unlike the AQI above it, which comes off an instrument. Hour by hour in Detroit → ## Ozone assembled over the water, blown back ashore The highest ozone readings in Michigan usually come from monitors within a few miles of Lake Michigan rather than from the interior. Precursor emissions from the urban corridor at the lake’s southern end drift out over water that stays colder than the land, sit in a shallow stable layer, react through the morning, and then the afternoon lake breeze carries the product back onshore in a narrow band. The gradient is steep: a concentration that trips an alert at the shoreline can fall off sharply a short distance inland. Multi-agency field work, including the 2017 Lake Michigan Ozone Study, was organized around that pattern specifically. Berrien County and parts of Allegan and Muskegon counties hold ozone nonattainment designations on that basis, all three reclassified to Serious in January 2025, so the worst ozone afternoon of a Michigan summer can be measured well away from the state’s industrial core. EPA proposed returning Berrien and Muskegon to attainment in July 2026. Detroit runs on different pollutants. The Detroit sulfur dioxide nonattainment area was drawn around the coke, steel and power generation along the lower Rouge and Detroit rivers; after reductions at those plants, EPA’s redesignation of the area to attainment took effect on April 2, 2026. The same corridor, plus the truck traffic feeding the international crossings, keeps diesel and industrial particulate in the same neighborhoods year-round. The Air Quality Division of the Michigan Department of Environment, Great Lakes, and Energy forecasts daily and issues air quality advisories. Smoke arriving from Canadian fires is a third pattern that answers to neither the lake nor the river. ## Where do these Michigan readings come from? 1 of the 2 metros here report from a named regulatory monitor — Southeast. 1 is running on modelled values instead, and it is labelled that way in the table. The dominant pollutant across Michigan today is O3 . We track 2 metropolitan areas in Michigan, not the whole state, and 1 of them has a page of its own. There is no state-wide average here on purpose: averaging 2 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 Michigan looks wrong the answer is often next door. ## Related Updated 14 Sep 2026, 22:12 UTC