Air quality · Montana
Air quality in Montana
Air quality (EPA AirNow) data for ZIP codes in Montana. Pick a ZIP below to dive into the air quality summary.
Last verified 2026-05-13 · methodology
What lands here
Pages show the current AQI category (Good, Moderate, Unhealthy for Sensitive Groups, Unhealthy, Very Unhealthy, Hazardous), the nearest reporting station, and historical averages.
Source & refresh
EPA AirNow. Refreshed hourly real-time / daily historical. Primary source →
Montana top concern
Radon Zone 1, wildfire
Montana is uniformly Zone 1 radon. Wildfire risk concentrates in the western mountains; the 2017 + 2021 + 2024 seasons all set records. EPA SDWIS shows compliance disparity between Helena/Missoula/Billings and small rural systems.
See Montana state page for the full state-level rollup across all 12 dimensions.
Read more on air quality
Editorial deep-dives explaining the source data, its limits, and how to read it.
AQI explained — what 50, 100, 150 actually mean for your lungs
Plain-English guide to the EPA Air Quality Index (AQI) and the 6 categories from Good to Hazardous. When to take precautions and which pollutants matter.
Wildfire Hazard Potential — what the USFS scale means and how to defend your home
Plain-English guide to the USDA Forest Service's Wildfire Hazard Potential 1–5 scale, how to read your community's risk, and concrete home-defense measures.
AirNow + wildfire smoke — when AQI is a real-time tool
How EPA AirNow handles real-time wildfire smoke, what the colors mean during fire season, and where AirNow leaves gaps you should know about.
AQI thresholds — what 'unhealthy for sensitive groups' actually means for you
EPA's AQI uses six bands keyed to specific population groups. Here's what each band means at the personal-decision level — go outside, mask, stay home.