*This unofficial 1-hour index
was derived from the PM2.5
AQI levels, which are based on a strong body of epidemiological evidence associating 24-hour PM2.5
exposures with respiratory and cardiovascular morbidity and mortality. For more information on the 1-hour AQI index, follow this link
**U.S. EPA 24-hour
National Air Quality Standard (NAAQS) of 35 µg/m3
. This value is based on the most recent 24-hour rolling average.