Air Quality in Ann Arbor, Michigan — Live

Live readings from PurpleAir sensors across Ann Arbor — with free alerts when summer ozone or wildfire smoke moves in.

Live Ann Arbor AQI from nearby PurpleAir sensors loads when this page opens in a browser, along with a live sensor map covering Ann Arbor and Ypsilanti, Saline, Dexter, Chelsea.

Ann Arbor's air is good most of the year — the city sits inland in a forested stretch of the Huron River valley, without the mountains or coastal fog that trap pollution in other parts of the country. What actually moves the needle here is summer ground-level ozone from heat and traffic on the I-94 and US-23 corridors, and — as June 2023 showed — wildfire smoke that can blow in from hundreds of miles away in Canada.

Canairy watches the sensors around your home, your kids' school, and everywhere else you care about, and tells you in plain English when the air changes enough to matter.

Why did the sky turn hazy in June 2023?

In June 2023, smoke from wildfires burning across Quebec and Ontario rode unusual northeast winds down into the Great Lakes, and Michigan's Department of Environment, Great Lakes, and Energy (EGLE) issued the state's first-ever PM2.5-based air quality alert on June 4. Ann Arbor's own reading hit 109 on the AQI scale — Unhealthy for Sensitive Groups — while Benton Harbor and Kalamazoo climbed even higher, to 132.

It kept happening. By late June, EGLE had issued back-to-back ozone and smoke alerts for the seven-county Detroit metro area, including Washtenaw County, through June 29 and 30 — the first time the state had ever posted two different pollutant warnings for the same region at once. "This is hopefully not the new normal," EGLE senior meteorologist Jim Haywood said at the time. "This is hopefully an outlier. But we don't know."

Ozone, not smoke, is the more familiar problem

Most summers, Ann Arbor's air trouble has nothing to do with fire. Ground-level ozone forms when tailpipe exhaust and other emissions cook in strong sunlight and heat, and it builds fastest along busy corridors like I-94 and US-23, where traffic backs up through the city every day. The American Lung Association's State of the Air report gives the wider Detroit-Warren-Ann Arbor metro area a failing grade for ozone, and its 2026 edition found the number of high-ozone days climbing rather than falling.

Michigan calls these Air Quality Action Days: EGLE issues one whenever ground-level ozone is forecast to cross the federal health standard of 70 parts per billion averaged over eight hours, mostly on hot, still, sunny days from late spring through early fall. On those days the advice is the same one Canairy sends automatically — move the run indoors and give the afternoon heat a pass.

The city started watching its own air block by block

In 2022, Ann Arbor's Office of Sustainability and Innovations began running its own ambient air monitoring network rather than relying only on the state's handful of regional stations. By September 2025 it had grown to ten solar-powered Clarity Node-S sensors positioned around the city, each reading fine particulate matter (PM2.5), nitrogen dioxide, and ozone, with two also tracking temperature, humidity, and wind.

The point, in the city's own words, is "hyper-local access to variations in air quality throughout the city" — proof that one downtown reading doesn't describe what's happening in every neighborhood. That's the same idea behind Canairy's approach: instead of one number for the whole metro, we read the sensors nearest the places you've actually saved, whether that's a home near the Huron Parkway or a kid's school off Packard.

Ann Arbor air quality FAQ

What is the air quality in Ann Arbor right now?

This page shows the current AQI for Ann Arbor, calculated from PurpleAir sensors across the city and updated continuously. The map below shows every live sensor, so you can check the reading closest to your own neighborhood.

Why did Ann Arbor's air quality get so bad in June 2023?

Wildfire smoke from Quebec and Ontario rode unusual northeast winds into Michigan, and the state issued its first-ever PM2.5 air quality alert on June 4, 2023. Ann Arbor's AQI reached 109 — Unhealthy for Sensitive Groups — and by late June the state was posting simultaneous ozone and smoke alerts for the Detroit metro area, including Washtenaw County, for the first time ever.

Does Ann Arbor have an ozone problem in summer?

Yes, more so than wildfire smoke in a typical year. Heat and traffic along corridors like I-94 and US-23 cook up ground-level ozone on hot, sunny days, and the American Lung Association's State of the Air report gives the wider Detroit-Warren-Ann Arbor metro area a failing grade for it. Michigan issues an Air Quality Action Day whenever ozone is forecast to cross the federal health standard.

What AQI level is unhealthy?

Under the US EPA scale, AQI 0–50 is Good and 51–100 is Moderate. From 101 the air is Unhealthy for Sensitive Groups — kids, older adults, and people with asthma or heart conditions — and above 150 it's Unhealthy for everyone. Canairy translates these numbers into a plain-English verdict, like whether to close the windows or move a workout indoors.

Where does Canairy's Ann Arbor data come from?

Readings come from PurpleAir's network of laser particle sensors across Ann Arbor and surrounding Washtenaw County towns, cross-referenced with government monitors and the Google Air Quality API. You can see every sensor behind your numbers on the live map - there's no black box.

Is Canairy free?

Yes. The Canairy app is free to download and includes live air quality for all your saved places, plain-English verdicts, and free push alerts when the air crosses your threshold. A paid plan adds extras like SMS text alerts.

Get Canairy free on Google Play.