Air Quality in Rochester, Minnesota — Live
Live readings from PurpleAir sensors across Rochester — with free alerts the moment Canadian wildfire smoke pushes the air unhealthy.
AQI 19 from 5 PurpleAir sensors · Holding steady · data from PurpleAir
As of , the air quality in Rochester, Minnesota is AQI 19 — Good and holding steady — with PM2.5 at 3.5 µg/m³, the median of 5 live PurpleAir sensors reading 9 to 39. 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 Rochester: weeds pollen is the strongest of the three at a high 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 Rochester and Byron, Stewartville, Pine Island, Oronoco. Every dot is a real sensor, color-coded by current air quality.
Sensor by sensor in Rochester
The sensors Canairy reads in Rochester agree right now — all 5 sit in the Good band, a 30-point spread — so the city-wide number is a fair description of the whole area today.
| From city center | AQI | Category |
|---|---|---|
| 1.4 mi WNW | 9 | Good |
| 1.4 mi N | 31 | Good |
| 1.7 mi WSW | 19 | Good |
| 2.7 mi NE | 19 | Good |
| 4.6 mi NNW | 39 | Good |
Rochester's air is clean most of the year — genuinely one of the better readings in Minnesota, helped along by a near-constant wind that keeps particle pollution from settling anywhere for long. The exception is summer, when smoke from wildfires burning hundreds of miles away in Canada can push the AQI from Good to unhealthy within a day, as it did twice during the record-setting 2023 fire season.
What Canairy does for Rochester
A clear verdict
Not just a number — a plain-English call for Rochester: 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 Rochester or across the country, on one screen.
Rochester's air is usually good, and the wind is a big reason why
Rochester sits in the valley of the South Fork Zumbro River, on the eastern edge of Minnesota's Driftless Area — the hilly, unglaciated corner of the state where retreating ice sheets left rolling bluffs and river cuts instead of flat till plains. That valley setting sounds like a recipe for stagnant air, but Rochester is also one of the windiest cities in the country, with average wind speeds around 12.6 mph. Wind that persistent doesn't let particle pollution sit and build the way it can in a sheltered basin.
On an ordinary day that shows up in the numbers: monitoring in Rochester regularly reads fine-particle (PM2.5) levels in the single digits, well under the World Health Organization's annual guideline, and among the cleanest readings tracked anywhere in Minnesota. Mayo Clinic and IBM Rochester, the city's two largest employers, aren't industrial pollution sources the way a refinery or a shipping port would be, so on a typical day there's no local smokestack or traffic corridor driving Rochester's air. The exception, and it's a real one, is smoke that blows in from somewhere else entirely.
The real story is smoke blown in from Canada
Minnesota logged a record 22 statewide air quality alerts covering 52 days in 2023 — nearly double the previous record set in 2021 — and Canadian wildfire smoke was behind almost all of them. Two of those alerts named Rochester directly. On May 18-19, 2023, a band of heavy ground-level smoke from wildfires burning in northern Alberta and Saskatchewan pushed southeastern Minnesota, including Rochester, into the Minnesota Pollution Control Agency's orange (unhealthy for sensitive groups) category while much of the rest of the state hit red.
Less than three weeks later, on June 5, 2023, smoke from wildfires in Quebec settled over the region again under very light winds, and MPCA issued another alert covering Rochester, the Twin Cities, Albert Lea, Mankato, Duluth, and several tribal nations. MPCA supervisory meteorologist Matt Taraldsen summed up why smoke has become the state's dominant air-quality problem: the Canadian fires driving it are 'just too widespread and too remote' to do anything about except watch the numbers. Five of the 2023 alerts were even triggered by ozone, which is unusual for Minnesota and a sign of how much volatile organic compound-laden smoke moved through that summer.
What to actually do when Rochester's air turns orange
MPCA's guidance during a smoke alert is specific: cut back on hard outdoor exertion, take more breaks, and consider moving practice, a run, or yard work indoors, especially if you're a kid, over 65, pregnant, or living with asthma, COPD, or heart disease. That advice mattered in southeast Minnesota twice in a single summer, even though the fires themselves were burning hundreds of miles away in Alberta, Saskatchewan, and Quebec — proof that the evacuation maps other states watch tell you nothing about what Rochester is actually breathing.
Rochester's extensive trail network along the Zumbro River and the Douglas Trail makes it an easy city to default to being outdoors in, which is exactly why it's worth checking the number before a hazy afternoon run rather than after. Canairy is built to make that a five-second check instead of a guessing game: set your threshold once, and it tells you when the air crosses it, and when it clears again.
Rochester air quality FAQ
What is the air quality in Rochester right now?
As of September 14, 2026 at 3:37 PM CDT, the air quality in Rochester, Minnesota is AQI 19 — Good — with PM2.5 at 3.5 µg/m³, the median of 5 live PurpleAir sensors. Open the windows. Great for outdoor activity.
Why did Rochester's air quality get so bad in the summer of 2023?
Minnesota had a record year for air quality alerts in 2023 — 22 of them covering 52 days statewide — and nearly all were caused by Canadian wildfire smoke. Rochester was named directly in at least two: an alert on May 18-19, 2023 for smoke from Alberta and Saskatchewan wildfires, and another on June 5, 2023 for smoke from Quebec wildfires that settled over southeast Minnesota under very light winds.
Does Rochester have local industrial air pollution, from IBM or Mayo Clinic?
Not in any way that shows up in the readings. Rochester's two largest employers aren't heavy industrial polluters, and on an ordinary day the city's fine-particle levels are among the lowest tracked anywhere in Minnesota, helped by winds that average 12.6 mph. Nearly every unhealthy air day Rochester has logged in recent years traces back to wildfire smoke blowing in from Canada, not anything local.
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 5 curated PurpleAir sensors Canairy tracks in and around Rochester, 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 Rochester
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