AQI (Air Quality Index):
A single number representing the overall air quality based on different pollutants, including PM, ozone, carbon monoxide, sulfur dioxide, and nitrogen dioxide.
The chart above is for Los Angeles, CA.
PM is a measurement of the concentration of particulate matter (PM2.5 or PM10) in the air, which is one factor contributing to the overall AQI. Use air quality alerts to understand when PM reaches harmful levels.
The chart above is for zip code 90025.