Air Quality in Milwaukee, Wisconsin — Live
Live readings from PurpleAir sensors across Milwaukee — with free alerts the moment smoke drifts in.
AQI 46 from 4 PurpleAir sensors · Trending down · data from PurpleAir
As of , the air quality in Milwaukee, Wisconsin is AQI 46 — Good and falling — with PM2.5 at 8.3 µg/m³, the median of 4 live PurpleAir sensors reading 45 to 55. 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 Milwaukee: weeds pollen is the strongest of the three at a moderate 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 Milwaukee and Wauwatosa, West Allis, Shorewood, Cudahy. Every dot is a real sensor, color-coded by current air quality.
Sensor by sensor in Milwaukee
The sensors Canairy reads in Milwaukee are 10 AQI points apart right now, from Good to Moderate, which is the whole reason one city-wide number can mislead you: the median describes air you may not be standing in.
| From city center | AQI | Category |
|---|---|---|
| 1.0 mi WSW | 51 | Moderate |
| 1.9 mi WNW | 45 | Good |
| 3.8 mi SSE | 55 | Moderate |
| 5.0 mi NW | 46 | Good |
Milwaukee's air is shaped by two things at once: its place on the western shore of Lake Michigan, and the wildfire smoke that now drifts down from Canada most summers. The lake that cools the city on a hot day also traps and cooks pollution along the shoreline into ozone, and in recent years the American Lung Association has handed the metro failing grades for both ozone and particle pollution.
What Canairy does for Milwaukee
A clear verdict
Not just a number — a plain-English call for Milwaukee: 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 Milwaukee or across the country, on one screen.
What the air in Milwaukee is doing next
| When | Expected air quality | Main pollutant |
|---|---|---|
| Today | Good | ozone |
| Tomorrow | Good | ozone |
| Monday | Good | ozone |
Forecast from EPA AirNow for the Milwaukee-Ozaukee 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.
Canadian wildfire smoke is now a regular part of Milwaukee summers
In June 2023, smoke from Canadian wildfires gave Milwaukee its worst air quality on record at the time. The DNR issued a multi-day advisory, Milwaukee and Waukesha counties were rated among the worst air in the nation, and residents could smell the smoke in the air. It was the moment a lot of people here realized wildfire haze was no longer just a western problem.
It did not stay a one-off. In July 2026, smoke from large fires in northern Minnesota and Ontario drifted in off the plains and pushed a Milwaukee reading to a hazardous AQI of 566, nearly double the 2023 record, with the DNR warning of very unhealthy to briefly hazardous air across Sheboygan, Milwaukee, Ozaukee, Kenosha and Racine counties. On days like that the smell and the haze are obvious, but the fine particles that do the damage are invisible, which is exactly why a sensor reading is worth more than a look out the window.
The lake breeze that cools the shore also cooks up ozone
Milwaukee has a summer ozone problem that is tied directly to Lake Michigan. On warm, sunny days a cool lake breeze develops off the water and pushes inland, and it can carry a dense ribbon of ozone with it along the shoreline. Ozone is not smoke you can see or smell at these levels; it forms when sunlight bakes traffic and industrial emissions, and the lake breeze concentrates it right where people live and exercise near the water.
This is well documented by the Wisconsin DNR and university researchers: the two monitors that regularly record the state's highest ozone, at Kohler-Andrae and Chiwaukee Prairie, both sit within a few hundred meters of the lake. It is a big reason the American Lung Association gave the Milwaukee metro an F for ozone in its 2025 report and ranked it 22nd worst in the nation the following year. A calm, sunny July afternoon can be a worse air day near the lakefront than a gray one.
An industrial city with an industrial legacy
Milwaukee grew up as a manufacturing city, and the Menomonee Valley was its engine, packed with tanneries, flour mills, meatpacking plants and rail yards. That history left a mark: an 1874 newspaper article called the Menomonee River the 'river of death,' and by the 1980s the valley had become the most visible brownfield in the state before a 133-acre redevelopment turned it around. The heavy tanning and rendering industries are gone, but the dense street grid, freeways and remaining industry still shape the everyday air.
Today the bigger daily contributors are traffic along the freeway corridors and the ozone that forms from those emissions in summer heat, layered on top of the wildfire smoke episodes. None of this makes Milwaukee's air unusually dangerous day to day, but it does mean the number moves around a lot: clean off the lake one morning, hazy from Canadian smoke by evening, and ozone-heavy on the next hot afternoon. That variability is the case for checking a live reading rather than assuming.
Milwaukee air quality FAQ
What is the air quality in Milwaukee right now?
As of September 5, 2026 at 9:49 AM CDT, the air quality in Milwaukee, Wisconsin is AQI 46 — Good — with PM2.5 at 8.3 µg/m³, the median of 4 live PurpleAir sensors. Open the windows. Great for outdoor activity.
Why does Milwaukee get so much wildfire smoke if there are no local fires?
The smoke comes from far away. On the right wind pattern, smoke from wildfires in Canada, Minnesota and Ontario drifts hundreds of miles south and settles over the Great Lakes. In June 2023 Canadian smoke gave Milwaukee its worst air on record at the time, and a July 2026 event from Minnesota and Ontario fires pushed a reading to a hazardous 566 AQI. These episodes can arrive within hours and the fine particles are invisible, so a live sensor reading tells you far more than looking at the sky.
Why is the air worse near the lakefront on hot sunny days?
Because of ozone. On warm, sunny days a cool lake breeze develops off Lake Michigan and pushes inland, carrying a ribbon of ozone along the shoreline. Ozone forms when sunlight bakes traffic and industrial emissions, and it is not something you can see or smell at these levels. It is a major reason the Milwaukee metro has repeatedly earned failing ozone grades from the American Lung Association, so a calm, sunny afternoon by the water can be a worse air day than a gray one.
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 4 curated PurpleAir sensors Canairy tracks in and around Milwaukee, 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 Milwaukee
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