Enter a US ZIP code for the live Air Quality Index — and plain-language guidance on what it means for you, your kids, and anyone who works outside.
| AQI | Category | What it means |
|---|---|---|
| 0–50 | Good | Air quality is satisfactory, and air pollution poses little or no risk. |
| 51–100 | Moderate | Air quality is acceptable. There may be a risk for some people, particularly those who are unusually sensitive to air pollution. |
| 101–150 | Unhealthy for Sensitive Groups | Members of sensitive groups may experience health effects. The general public is less likely to be affected. |
| 151–200 | Unhealthy | Some members of the general public may experience health effects; members of sensitive groups may experience more serious health effects. |
| 201–300 | Very Unhealthy | Health alert: the risk of health effects is increased for everyone. |
| 301+ | Hazardous | Health warning of emergency conditions: everyone is more likely to be affected. |
Readings come directly from EPA AirNow, the U.S. interagency system that publishes hourly observations from official monitoring stations. We report the monitoring area nearest your ZIP code and, following AirNow's convention, headline the highest current pollutant AQI.
Activity guidance follows the EPA's AQI activity guides, restated in plain language for four audiences: everyone, sensitive groups, children, and outdoor workers. Respiratory-protection notes describe filtration certifications only — ASTM F3502-21 and KN95-class filtration are tested standards for fine-particle (PM2.5) filtration. This tool provides general environmental information, not medical advice.
Built by AirPop, makers of ASTM F3502-21 certified air wearables. See how our filtration is tested →
Readings come live from EPA AirNow, the U.S. government system that aggregates official monitoring stations run by EPA, state, local, and tribal air agencies. We show the highest current pollutant AQI for the monitoring area nearest your ZIP code, the same convention AirNow uses.
AQI 101–150 is Unhealthy for Sensitive Groups — children, older adults, pregnant people, and anyone with a heart or lung condition should shorten and lighten outdoor activity. At AQI 151+ (Unhealthy), everyone may begin to feel effects and should reduce prolonged outdoor exertion. At 201+ (Very Unhealthy), avoid outdoor activity.
EPA guidance suggests sensitive groups consider a well-fitted mask with certified particle filtration from AQI 101, and recommends certified protection for anyone spending sustained time outdoors at AQI 151+. Filtration certification matters: KN95-class and ASTM F3502-21 rated masks are tested against fine particles; cloth and surgical masks are not effective against PM2.5.
Wildfire smoke is mostly fine particulate matter — particles 2.5 micrometers and smaller (PM2.5) that stay airborne for days and penetrate deep into the lungs. During smoke events, PM2.5 is almost always the pollutant driving the AQI.
Official monitoring stations report hourly. This tool refreshes its data at most every 30 minutes, so what you see reflects the latest published observation for your area.
Wildfire season resource: choosing a mask that actually filters smoke · The bigger picture: AirPop's approach to breathing health