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.

Live Rochester AQI from nearby PurpleAir sensors loads when this page opens in a browser, along with a live sensor map covering Rochester and Byron, Stewartville, Pine Island, Oronoco.

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.

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.

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, MN right now?

This page shows the current AQI for Rochester, 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 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.

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 Rochester data come from?

Readings come from PurpleAir's network of laser particle sensors across Rochester and surrounding 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.

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.

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