Nitrogen Dioxide (NO2) Pollution

Technical Data and Reports on Nitrogen Dioxide Measurements and SIP Status

EPA collects data from the states and regions on their air quality and state implementation plan (SIP) progress. This information is compiled in a database, and used to create reports, trend charts, and maps.

SIP status reports

Note: since there are currently no nonattainment areas for NO2, reports are only available on infrastructure SIPs for this pollutant.

Reports for infrastructure SIP requirements

SIPs approved by EPA

Air quality data

AirNow: see real-time air pollution data in the United States.

Air Quality Trends: View trends for nitrogen dioxide levels in ambient air; measured nationally, regionally, and locally; up to 2015.

Design Values: view statistics that describe the air quality status of a given area relative to the level of EPA's National Ambient Air Quality Standards. These Excel reports are listed by pollutant.


  • NO2 Designations: This web site provides information on the process EPA, the states, and the tribes follow to designate areas as "attainment" (meeting) or "nonattainment" (not meeting) the nitrogen dioxide standards.
  • Green Book: listings of areas designated nonattainment for each NAAQS pollutant. It includes current designation and classification status, area maps, reports, and Federal Register notices.