Air Quality in Billings, Montana — Live
Live readings from PurpleAir sensors across Billings — with free alerts when refinery smog, winter inversions, or wildfire smoke move in.
AQI 1 from 4 PurpleAir sensors · Trending down · data from PurpleAir
As of , the air quality in Billings, Montana is AQI 1 — Good and falling — with PM2.5 at 0.1 µg/m³, the median of 4 live PurpleAir sensors reading 1 to 9. 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 Billings: weeds pollen is the strongest of the three at a moderate 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 Billings and Laurel, Lockwood, Shepherd, Huntley. Every dot is a real sensor, color-coded by current air quality.
Sensor by sensor in Billings
The sensors Canairy reads in Billings agree right now — all 4 sit in the Good band, a 8-point spread — so the city-wide number is a fair description of the whole area today.
| From city center | AQI | Category |
|---|---|---|
| 1.6 mi W | 1 | Good |
| 4.2 mi ENE | 9 | Good |
| 4.4 mi WSW | 1 | Good |
| 5.1 mi NNE | 1 | Good |
Billings sits in the Yellowstone River valley, boxed in by the sandstone Rimrocks to the north and east, and most of the year the air here is unremarkable in the best sense. What sets it apart from a typical Montana town is industry: Billings and neighboring Laurel host three of Montana's four oil refineries, and the area has spent decades under a federal cleanup plan for sulfur dioxide. Add in winter nights when the valley traps cold, still air under a temperature inversion, plus a few weeks most summers when wildfire smoke - Montana's own or drifted down from Canada - fills the valley, and an otherwise mild climate gets a handful of genuinely bad-air stretches every year.
What Canairy does for Billings
A clear verdict
Not just a number — a plain-English call for Billings: 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 Billings or across the country, on one screen.
The Rimrocks box the valley in
Billings sits around 3,100 to 3,200 feet above sea level in the Yellowstone River valley, hemmed in by the Rimrocks - sandstone cliffs that rise roughly 500 feet along downtown's north edge and as much as 800 feet near the airport to the east. That terrain does more than separate downtown from the Heights and Lockwood; on calm, clear winter nights it helps trap a shallow layer of cold, dense air right at the valley floor while warmer air sits above it, a classic temperature inversion.
When that sets up, whatever is in the air - vehicle exhaust, wood smoke, refinery emissions - has nowhere to vent, and PM2.5 can build for days until a Chinook wind or a passing storm finally scours the valley out. It's the same basic mechanism that gives a lot of Rocky Mountain valley towns their worst air days, just with an unusually specific added ingredient in Billings' case: heavy industry sitting inside the same bowl.
Billings and Laurel share a federal cleanup plan for refinery pollution
Yellowstone County is home to three of Montana's four oil refineries - the Phillips 66 refinery in Billings, the CHS Inc. refinery in Laurel, and the Par Montana refinery (formerly ExxonMobil) just east of the city in Lockwood. Sulfur dioxide from these plants got the Billings/Laurel area designated nonattainment under the Clean Air Act back in 1978, and the EPA still runs a Federal Implementation Plan covering four major sources in the two towns to keep SO2 in check - the agency finalized the latest round of revisions to that plan in January 2025.
In practice, that means Billings' air story isn't only about wildfire smoke the way it is in a lot of Western cities - there's an industrial fingerprint too, most noticeable on still days when a refinery flare or upset condition can push SO2 or particulates up over one part of the valley rather than the city as a whole. It's also why a single official monitor a few miles from a refinery tells you less than a dense set of sensors that includes readings closer to Laurel and Lockwood, not just downtown.
Wildfire smoke still finds the valley most summers
Montana's own wildfire season and drifting Canadian smoke both find their way into the Yellowstone Valley. In early September 2023, smoke pushed south from wildfires burning across Canada and degraded air quality across most of Montana, Yellowstone County included, prompting a statewide air quality alert that lasted for days.
Billings also sits close enough to central and western Montana's fire country that a bad fire season anywhere in the state can put a haze over the city, even when nothing is burning nearby. Ground-level ozone, by contrast, is a minor factor here compared to particulate pollution - Billings gets plenty of summer heat, but it's the combination of smoke, refinery emissions, and winter inversions, not photochemical smog, that drives the valley's worst air-quality days.
Billings air quality FAQ
What is the air quality in Billings right now?
As of September 14, 2026 at 6:09 AM MDT, the air quality in Billings, Montana is AQI 1 — Good — with PM2.5 at 0.1 µg/m³, the median of 4 live PurpleAir sensors. Open the windows. Great for outdoor activity.
Why does Billings get winter temperature inversions?
Billings sits in the Yellowstone River valley, boxed in by the Rimrocks - sandstone cliffs that rise 500 to 800 feet along downtown's north and east edges. On calm, clear winter nights, cold air pools at the valley floor while warmer air sits above it, trapping vehicle exhaust, wood smoke, and other pollutants close to the ground until a Chinook wind or a storm system clears it out.
Does refinery pollution affect Billings' air quality?
Yes. Yellowstone County has three of Montana's four oil refineries - in Billings, Laurel, and Lockwood - and the area has operated under a federal Clean Air Act plan for sulfur dioxide since the Billings/Laurel area was designated nonattainment in 1978, with the EPA finalizing the latest update to that plan in January 2025. Canairy's sensor network lets you check readings near Laurel and Lockwood specifically, not just downtown Billings.
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 4 curated PurpleAir sensors Canairy tracks in and around Billings, 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 Billings
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