Some of NDEP's monitor data is presented in "near real-time" (hourly basis) on this page using the Air Quality Index (AQI). The AQI is an index for reporting air quality for various pollutants. The AQI is divided into six categories represented by a color and numerical range. Mouse over each category in the AQI index below to receive the numerical range and a description. More information about AQI is available on the AQI Home Page and in the EPA document AQI: A Guide to Air Quality and Your Health [PDF]. Clark and Washoe counties have monitoring data available on their web sites.