Air Quality in Bozeman, Montana — Live
Live readings from PurpleAir sensors across Bozeman — with free alerts when summer smoke or winter inversions move in.
AQI 0 from 5 PurpleAir sensors · Trending down · data from PurpleAir
As of , the air quality in Bozeman, Montana is AQI 0 — Good and falling — with PM2.5 at 0.0 µg/m³, the median of 5 live PurpleAir sensors reading 0 to 2. 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 Bozeman: 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 Bozeman and Belgrade, Livingston, Manhattan, Big Sky. Every dot is a real sensor, color-coded by current air quality.
Sensor by sensor in Bozeman
The sensors Canairy reads in Bozeman agree right now — all 5 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 |
|---|---|---|
| 0.4 mi SW | 0 | Good |
| 2.1 mi WNW | 0 | Good |
| 3.0 mi WNW | 0 | Good |
| 5.0 mi WSW | 0 | Good |
| 5.8 mi NW | 2 | Good |
Bozeman's air is clean most of the year, and the numbers back that up: recent monitoring shows roughly 97 percent of days here fall within the World Health Organization's safe limits, with an average AQI in the high 20s. The exceptions are two very different seasons - a few weeks of wildfire smoke most summers, almost none of it from fires actually burning in Gallatin County, and the still, cold winter nights when the valley traps its own wood smoke instead.
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Bozeman usually gets the mild version of Montana's smoke seasons
Montana's benchmark bad year for smoke is 2017, and it shows how uneven the impact can be even within one state. On September 13 of that year, the Montana Department of Environmental Quality issued a statewide air quality alert for wildfire smoke - but Bozeman's own monitor read Moderate that day, a 24-hour average of 32.4 micrograms per cubic meter of fine particulate. A hundred and fifty miles northwest, the town of Seeley Lake spent 49 days under hazardous smoke that same fire season, air so thick that monitoring equipment reportedly couldn't measure the top of it.
That gap is the pattern locals have come to expect: Bozeman sits high - about 4,800 feet - in a valley that catches wind more often than it stagnates, so smoke drifting in from fires in Idaho, the Pacific Northwest, western Montana, or some summers Canada tends to pass through rather than settle for weeks. It still shows up most Julys and Augusts, sometimes pushing the AQI into Moderate or Unhealthy for Sensitive Groups territory for a few days at a stretch, but Bozeman rarely sees the sustained hazardous readings that hit more enclosed valley towns in the same fire seasons.
Winter brings the other kind of bad air: the inversion
Bozeman's geography creates a different problem once the snow flies. As the local outdoor magazine Outside Bozeman has explained, a clear, calm winter night lets the valley floor radiate its heat away fast, cooling the ground below the air above it - the reverse of how temperature normally works with altitude. Because Bozeman sits in genuinely mountainous terrain, with the Bridger Range to the north and the Gallatin Range and Hyalite Peaks to the south, cold air drains downhill off those peaks and pools in the valley overnight, building into a thick inversion layer that can linger for days rather than burning off by mid-morning.
That trapped layer doesn't just make fog - it holds whatever gets mixed into it near the ground. Montana's state health department specifically calls out wood-burning stoves, widely used for home heating here, as a major source of the fine particulate that builds up in valleys during these winter inversions, along with vehicle exhaust along the valley floor. It's a quieter problem than summer smoke, without the dramatic orange sky, but it's the reason a clear, cold, windless week in January can still mean noticeably worse air than a windy one.
Bozeman air quality FAQ
What is the air quality in Bozeman right now?
As of September 14, 2026 at 6:10 AM MDT, the air quality in Bozeman, Montana is AQI 0 — Good — with PM2.5 at 0.0 µg/m³, the median of 5 live PurpleAir sensors. Open the windows. Great for outdoor activity.
Why does Bozeman's air get smoky in summer?
Most of Bozeman's smoke doesn't start here. Fires burning in Idaho, the Pacific Northwest, elsewhere in Montana, or Canada can drift over the Gallatin Valley in July and August. Bozeman's elevation and wind usually keep it from settling as badly as it does in more enclosed valley towns, but it can still push the AQI into Moderate or Unhealthy for Sensitive Groups territory for days at a time in a bad fire year.
Do winter temperature inversions affect Bozeman's air quality?
Yes. On calm, cold winter nights, cold air drains down off the Bridger Range and Gallatin Range into the valley floor and pools there, sometimes for days. That trapped layer holds onto whatever's in the air near the ground - mostly smoke from wood-burning stoves and vehicle exhaust - which is why a still, clear week in January can quietly have worse air than a windy one, even without any visible haze.
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 Bozeman, 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 Bozeman
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