Air Quality in Bozeman, Montana — Live

Live readings from PurpleAir sensors across Bozeman — with free alerts when summer smoke or winter inversions move in.

Live Bozeman AQI from nearby PurpleAir sensors loads when this page opens in a browser, along with a live sensor map covering Bozeman and Belgrade, Livingston, Manhattan, Big Sky.

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.

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.

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?

This page shows the current AQI for Bozeman, calculated from PurpleAir sensors across the city and Gallatin Valley and updated continuously. The map below shows every live sensor, so you can check the reading closest to your own neighborhood.

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 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 Bozeman data come from?

Readings come from PurpleAir's network of laser particle sensors across Bozeman 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.

Get Canairy free on Google Play.