Air Quality Forecast

COG, in partnership with the District Department of Energy & Environment, Maryland Department of the Environment, and Virginia Department of Environmental Quality, provides daily air quality forecasts for the metropolitan Washington region. Forecasts are available year-round and are based on the national Air Quality Index.  

Additional Air Quality Resources

  • Visit Clean Air Partners to sign up for Air Quality Email Notifications, download the Air Quality App, and get involved to help protect your health and the environment.
  • For Washington Air Quality Forecasts, you can also dial (703) 996-2200, select Option 1 - then select Option 7. (Provided by NOAA/National Weather Service, Baltimore/Washington Forecast Office located in Sterling, VA)
  • Visit COG's Air Quality Planning Areas page for air quality news, documents, committees, and meeting information.  

Air Quality Data

Air Quality Index

The Air Quality Index (AQI) is a national index for reporting forecasted and daily air quality. It explains how clean or polluted the air is, and highlights associated health concerns. The AQI focuses on health effects that can happen within a few hours or days after breathing polluted air. It is divided into several color-coded categories, which correspond to different levels of health concerns.

Air Quality Index
Levels of Health Concern





Air quality is considered good, and air pollution poses little or no risk.



Air quality may pose a moderate health risk, especially for those who are unusually sensitive to air pollution.

Unhealthy for
Sensitive Groups


Members of sensitive groups, children and adults with respiratory and heart ailments, may experience health effects and should limit time spent outside. The general public is not likely to be affected.



Everyone may experience health effects and should limit their outdoor activity; members of sensitive groups may experience more serious health effects.

Very Unhealthy


Everyone may experience more serious health effects and should avoid outdoor activities, especially individuals with heart and breathing ailments, children, and older adults.