Air Quality in Green Bay, Wisconsin — Live
Live readings from PurpleAir sensors across Green Bay — with free alerts the moment smoke drifts in.
AQI 62 from 2 PurpleAir sensors · Holding steady · data from PurpleAir
As of , the air quality in Green Bay, Wisconsin is AQI 62 — Moderate and holding steady — with PM2.5 at 15.0 µg/m³, the median of 2 live PurpleAir sensors reading 52 to 71. Canairy's verdict: Mostly clear.
For scale, that PM2.5 reading is about 1.0 times 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 Green Bay: 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 Green Bay and De Pere, Ashwaubenon, Bellevue, Howard. Every dot is a real sensor, color-coded by current air quality.
Sensor by sensor in Green Bay
The sensors Canairy reads in Green Bay agree right now — all 2 sit in the Moderate band, a 19-point spread — so the city-wide number is a fair description of the whole area today.
| From city center | AQI | Category |
|---|---|---|
| 5.5 mi ESE | 71 | Moderate |
| 8.5 mi NNW | 52 | Moderate |
Green Bay usually breathes easy. Sitting where the Fox River empties into the bay off Lake Michigan, the city has generally good air most of the year, and the two things that change that are both worth watching: smoke that drifts down from Canadian wildfires in summer, and the industrial legacy of a river valley packed with paper mills.
What Canairy does for Green Bay
A clear verdict
Not just a number — a plain-English call for Green Bay: 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 Green Bay or across the country, on one screen.
What the air in Green Bay is doing next
| When | Expected air quality | Main pollutant |
|---|---|---|
| Today | Good | ozone |
| Tomorrow | Good | ozone |
| Monday | Good | ozone |
Forecast from EPA AirNow for the Green Bay and Fox Cities 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.
The smoke that rolls in from Canada
Green Bay's worst air days rarely start anywhere nearby. In June 2023, smoke from Canadian wildfires pushed south across the Great Lakes and triggered air quality alerts across the Upper Midwest, including Wisconsin. That same stretch of late spring and early summer produced the highest ozone levels ever recorded at a regional scale across the Upper Midwest, a reminder that wildfire smoke does not just cloud the sky, it reshapes the chemistry of the air for days at a time.
Because these events arrive on the wind rather than from a local smokestack, they can turn a clear morning into an unhealthy afternoon with little warning. The Wisconsin DNR issues advisories during smoke episodes, but the timing and intensity shift hour by hour. That is exactly the kind of change a live sensor near your own street will catch before a regional forecast does.
A paper town on a working river
Green Bay grew up on paper. The city once carried the nickname 'Toilet Paper Capital of the World,' and Northern Paper Mills, founded here in 1901, became the largest toilet paper producer in the world by 1920. Georgia-Pacific and Procter & Gamble still run mills in the city, and Green Bay sits at the downstream end of one of the densest paper corridors in the country.
Follow the Fox River upstream toward Appleton, Neenah, and Kaukauna and you pass roughly two dozen paper and pulp mills that together turn out more than five million tons of paper a year and employ around fifty thousand people. That concentration of combustion and processing is part of the region's air story, alongside the traffic and rail that keep a manufacturing economy moving. Baseline readings in the city are usually good, but a working industrial valley is a reason to keep an eye on the sensor closest to you rather than assume a citywide average tells your block's story.
The bay, the breeze, and the Fox River valley
Green Bay's geography cuts both ways for air quality. The city sits at the mouth of the Fox River on the bay off Lake Michigan, and the lake and bay breeze can push cleaner air onshore or, on the wrong day, trap and funnel pollution along the water and up the river valley. Ozone in particular tends to build over the lake and drift toward shoreline communities on hot, still afternoons.
The Wisconsin DNR points to ozone and fine particle pollution, PM2.5, as the two pollutants that matter most here, and it monitors both across the state. Those are also the two things that spike during a smoke event or a stagnant summer high. Knowing which one is elevated, and where, is the difference between closing the windows and heading out for a run.
Green Bay air quality FAQ
What is the air quality in Green Bay right now?
As of September 5, 2026 at 9:49 AM CDT, the air quality in Green Bay, Wisconsin is AQI 62 — Moderate — with PM2.5 at 15.0 µg/m³, the median of 2 live PurpleAir sensors. Sensitive groups may want to take it slower outside.
Why does Green Bay get wildfire smoke when there are no fires nearby?
The smoke travels. In June 2023, smoke from Canadian wildfires drifted south across the Great Lakes and triggered air quality alerts across the Upper Midwest, including Wisconsin, and that stretch produced the highest regional ozone levels the Upper Midwest has ever recorded. A fire hundreds of miles north can leave Green Bay under a haze for days, which is why watching a live local reading beats guessing from the sky.
Does Green Bay's paper industry affect the air?
Green Bay is a longtime paper-manufacturing center, once called the 'Toilet Paper Capital of the World,' with mills still run by Georgia-Pacific and Procter & Gamble, and the Fox River valley upstream holds roughly two dozen more paper and pulp mills. Day-to-day readings in the city are usually good, but a dense industrial corridor is a reason to check the sensor nearest you rather than rely on a citywide average.
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 2 curated PurpleAir sensors Canairy tracks in and around Green Bay, 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 Green Bay
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