Air quality · Colorado
Air quality in Colorado
Air quality (EPA AirNow) data for ZIP codes in Colorado. 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 →
Colorado top concern
Radon Zone 1, wildfire on the Front Range
Colorado is one of the most uniformly Zone 1 radon states in the US. WUI wildfire risk concentrates along the Front Range from Boulder to Colorado Springs. Drinking water sourcing splits between Front Range water districts and Western Slope reclamation projects, each with distinct EPA SDWIS compliance histories.
See Colorado 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.