Air Quality in Butte, Montana — Live
Live readings from PurpleAir sensors across Butte — with free alerts when mine dust or winter smoke moves in.
AQI 3 from 2 PurpleAir sensors · Holding steady · data from PurpleAir
As of , the air quality in Butte, Montana is AQI 3 — Good and holding steady — with PM2.5 at 0.6 µg/m³, the median of 2 live PurpleAir sensors reading 2 to 4. 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 is quiet in Butte right now. Google's pollen forecast covers this area and shows no tree, grass or weed activity today — which is a real answer, not missing data.
Free to download · Live data from PurpleAir & public monitors
Live PurpleAir sensor map for Butte and Walkerville, Anaconda, Whitehall, Deer Lodge. Every dot is a real sensor, color-coded by current air quality.
Sensor by sensor in Butte
The sensors Canairy reads in Butte agree right now — all 2 sit in the Good band, a 2-point spread — so the city-wide number is a fair description of the whole area today.
| From city center | AQI | Category |
|---|---|---|
| 9.0 mi ENE | 4 | Good |
| 10.2 mi NE | 2 | Good |
Butte's air is shaped more by what's underfoot than what's on fire. A century of copper mining under the Anaconda Company left the city with a dust problem serious enough that the EPA once classified it as a PM10 nonattainment area, and the Continental Pit mine still runs today just north of downtown. Add cold winter nights that trap wood smoke in the valley, plus a few smoky weeks most summers when western Montana's wildfire season kicks up, and you get a place where the air is fine most days but has real, specific reasons when it isn't.
What Canairy does for Butte
A clear verdict
Not just a number — a plain-English call for Butte: 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 Butte or across the country, on one screen.
Butte's dust problem didn't end when the mines closed
A century of copper mining and smelting under the Anaconda Company left Butte with enough airborne particulate that the EPA designated the city a moderate nonattainment area for PM10 on March 15, 1991. For decades afterward, monitors at the Greeley School site on the north side of town tracked whether cleanup and dust-control work were actually paying off.
They were: using five years of data from 2014 through 2018, Montana's Department of Environmental Quality petitioned the EPA, and on July 26, 2021 Butte was reclassified out of nonattainment and into a maintenance plan. That's real, measurable progress - but it's also why Butte-Silver Bow still runs continuous PM10 monitoring at Greeley today rather than treating the issue as closed history.
The Continental Pit still runs, and Greeley feels it
Montana Resources' Continental Pit - an active open-pit copper and molybdenum mine - is the only mining operation still working the ground at Butte, and it sits close enough to the Greeley neighborhood that only a two-lane road separates the pit from roughly 700 homes. Fugitive dust blowing off the mine is a present-day concern for those residents, not a relic of the smelter era.
In late 2023, the Greeley Neighborhood Community Development Corporation surveyed residents with grant funding from the Center for Health, Environment & Justice, and pinpointed the specific streets where people worried most about dust drifting over from the pit. Montana Resources responded by starting monthly dustfall sampling that August at Pine Street, Walnut Street, and the Greeley School site, and told the Butte-Silver Bow Board of Health it would help fund research into the health effects of mine dust.
Winter adds wood smoke to a valley that already holds its air
Butte sits at almost 5,800 feet in a mountain-ringed valley on the Continental Divide, and on cold, calm nights that terrain lets cool air pool near the ground instead of mixing out - a classic winter inversion. Butte-Silver Bow's own air quality program warns that just 20 old, non-EPA-certified wood stoves can put more than a ton of fine particle pollution into a neighborhood over the cold months, which is why the county has a standing Air Quality Control Ordinance covering residential wood heaters.
Summer brings a different, more borrowed problem: wildfire smoke. Butte isn't usually ground zero for a fire the way some Montana towns are, but it shares the same regional smoke seasons - 2017's stretch of haze across western Montana, remembered locally as the state's worst 'summer of smoke,' settled over the Butte area for weeks even though the largest fires were burning near Missoula and the Bitterroot. Montana DEQ's statewide smoke forecasts exist because a clear Butte morning can turn hazy by afternoon from a fire burning nowhere near Silver Bow County.
Butte air quality FAQ
What is the air quality in Butte right now?
As of September 14, 2026 at 6:09 AM MDT, the air quality in Butte, Montana is AQI 3 — Good — with PM2.5 at 0.6 µg/m³, the median of 2 live PurpleAir sensors. Open the windows. Great for outdoor activity.
Why does the Greeley neighborhood worry about dust from the mine?
Montana Resources' Continental Pit, an active copper and molybdenum mine, sits just across a two-lane road from roughly 700 homes in Greeley. A 2023 resident survey identified specific streets most concerned about fugitive dust, and Montana Resources now runs monthly dustfall sampling at Pine Street, Walnut Street, and Greeley School to track it.
Does Butte still have a mining-related air pollution problem?
It's much improved but still monitored. The EPA designated Butte a PM10 nonattainment area in 1991 because of dust tied to a century of mining and smelting. Cleanup progress was strong enough that the city was reclassified to attainment under a maintenance plan in 2021, and continuous PM10 monitoring continues at the Greeley School site today.
Why does Butte's air get worse on cold winter nights?
Butte sits nearly a mile high in a mountain-ringed valley, and on calm winter nights a temperature inversion traps cold air - and wood smoke from home stoves and fireplaces - close to the ground instead of letting it mix away. Butte-Silver Bow's air quality program notes that just 20 old, uncertified wood stoves can add more than a ton of fine particle pollution to a neighborhood over the cold season.
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 Butte, 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 Butte
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