About Clean Air Data

Clean Air Data provides real-time air quality information for cities and ZIP codes across the United States, powered by official EPA AirNow monitoring data.

Our Data Source

All air quality data comes directly from the U.S. Environmental Protection Agency's (EPA) AirNow program — the official source for air quality information in the United States. The AirNow network includes thousands of monitoring stations across the country, providing hourly updates on pollutant levels including PM2.5, PM10, ozone, CO, NO2, and SO2.

Understanding AQI

The Air Quality Index (AQI) is a scale from 0 to 500 that measures how clean or polluted the air is. The higher the AQI value, the greater the level of air pollution and the greater the health concern.

0–50: Good — Air quality is satisfactory.
51–100: Moderate — Acceptable; some pollutants may affect sensitive groups.
101–150: Unhealthy for Sensitive Groups
151–200: Unhealthy — Everyone may experience effects.
201–300: Very Unhealthy — Health alert.
301+: Hazardous — Emergency health conditions.

Contact

For questions or feedback, please visit our homepage or reach us at contact@cleanairdata.org.