Air Quality in Great Falls, Montana — Live
Live readings from PurpleAir sensors across Great Falls — with free alerts when wildfire smoke drifts in on the wind.
AQI 1 from 3 PurpleAir sensors · Trending down · data from PurpleAir
As of , the air quality in Great Falls, Montana is AQI 1 — Good and falling — with PM2.5 at 0.2 µg/m³, the median of 3 live PurpleAir sensors reading 0 to 13. 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 Great Falls: 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 Great Falls and Black Eagle, Belt, Cascade, Vaughn. Every dot is a real sensor, color-coded by current air quality.
Sensor by sensor in Great Falls
The sensors Canairy reads in Great Falls agree right now — all 3 sit in the Good band, a 13-point spread — so the city-wide number is a fair description of the whole area today.
| From city center | AQI | Category |
|---|---|---|
| 0.7 mi WNW | 13 | Good |
| 7.3 mi WSW | 2 | Good |
| 12.0 mi S | 0 | Good |
Great Falls sits out on the open plains where the Missouri River drops over its namesake falls, with nothing like the enclosed valley that traps smoke in towns on the west side of Montana. Most days the air here is genuinely good, and wind is the reason why - Great Falls is regularly ranked among the windiest cities in the country. The exception comes when that same wind turns into a delivery system, carrying wildfire smoke in from Idaho, British Columbia, Alberta, or wherever the West's fire season happens to be burning that year.
What Canairy does for Great Falls
A clear verdict
Not just a number — a plain-English call for Great Falls: 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 Great Falls or across the country, on one screen.
Great Falls' air is clean mostly because of the wind, not despite it
Sitting on the plains at about 3,333 feet with the Rocky Mountain Front rising just to the west, Great Falls has none of the bowl-shaped geography that lets smoke and haze pool over west-side Montana towns like Missoula. Instead the city is known for its wind: NOAA's 1991-2020 climate normals put its average wind speed at roughly 12.5 mph, among the highest of any US city, with gusts along the immediate Rocky Mountain Front regularly topping 70 mph. That constant movement is ordinarily a clean-air asset - pollution doesn't get the chance to sit still and build up.
The city's own history leaned on that same logic. The Anaconda copper smelter that operated in the Black Eagle neighborhood from 1890 to 1980 built a 506-foot smokestack in 1908 - the tallest chimney in the world at the time - specifically to loft its fumes high enough for the plains wind to carry them away rather than let them settle over the city. The smelter is long gone, but the same wind that once dispersed its smoke is still the biggest reason Great Falls posts far more Good and Moderate AQI days than Unhealthy ones.
The real risk is smoke blown in from somewhere else
When Great Falls does have a bad air day, it's rarely a local fire - it's smoke arriving on the wind from hundreds of miles away. In July 2021, Great Falls and Cut Bank were both listed at Unhealthy air quality as smoke from fires burning across Montana and the wider West combined. By August, Montana DEQ was advising residents to stay indoors as a northwesterly flow pushed smoke from wildfires in Idaho and British Columbia across the state, and by September 9-10 that year a stalled upper-level high had pivoted smoke and haze from southwestern Montana and Idaho fires over a 20-county stretch running from Missoula through Helena, Butte, Bozeman, and Great Falls, holding conditions at Unhealthy for days.
Canadian wildfires have become the more recent version of the same pattern. Smoke from more than a hundred fires burning across Canada spread into Montana in May 2023, and on September 3, 2025, Montana DEQ was again tracking winds funneling Canadian wildfire smoke across most of the state. The mechanism is consistent: the same northwesterly and westerly winds that usually keep Great Falls' air clean can, under the right upper-air pattern, turn into a conveyor belt for smoke that started a fire season away.
Who should watch it closest here
Malmstrom Air Force Base sits on the city's northeast edge and is home to thousands of Air Force families, many new to Montana and unfamiliar with the summer smoke pattern longtime residents have learned to watch for. Farm and ranch workers across Cascade County's wheat country - Great Falls is home to both the Montana Wheat and Barley Committee and the state's only federally licensed grain-testing lab, the Montana State Grain Laboratory - also spend full harvest days outdoors, which makes the difference between a Moderate and an Unhealthy-for-Sensitive-Groups reading more than academic.
The habit longtime locals have learned: check the number before committing to a long outdoor day, not after the horizon turns hazy. Smoke arriving from Idaho, British Columbia, or Alberta can show up as a change in the light before it shows up as a smell, and by the time Great Falls' famous wind is obviously pushing haze down the street, the air has usually already turned for the worse.
Great Falls air quality FAQ
What is the air quality in Great Falls right now?
As of September 14, 2026 at 6:10 AM MDT, the air quality in Great Falls, Montana is AQI 1 — Good — with PM2.5 at 0.2 µg/m³, the median of 3 live PurpleAir sensors. Open the windows. Great for outdoor activity.
Why does Great Falls get smoky when the fires aren't even in Montana?
Great Falls sits on open plains with none of the enclosed valleys that trap smoke in western Montana towns, so its air quality depends heavily on the wind - and that same wind can carry smoke in from hundreds of miles away. Fires in Idaho, British Columbia, and Alberta pushed Great Falls to Unhealthy AQI readings during stretches of July and September 2021, and Canada's unusually active 2023 and 2025 fire seasons both sent smoke into the city even though nothing was burning nearby.
Is Great Falls really one of the windiest cities in the US?
Yes. NOAA's 1991-2020 climate normals put Great Falls' average wind speed at roughly 12.5 mph, among the highest of any US city, with gusts along the nearby Rocky Mountain Front regularly topping 70 mph. That wind is normally good news for air quality since it keeps pollution from sitting still, but it's also the reason wildfire smoke from other states and Canada can arrive here so quickly.
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 3 curated PurpleAir sensors Canairy tracks in and around Great Falls, 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
Go deeper
Air quality near Great Falls
We watch Great Falls's air. You live your life.
Set your threshold once and get a heads-up only when the air actually changes for you. Free on the App Store & Google Play.