AQI: Good (0 - 50) AQI: Good (0 - 50)
Air quality is considered satisfactory, and air pollution poses little or no risk.
AQI: Moderate (51 - 100) AQI: Moderate (51 - 100)
Air quality is acceptable; however, for some pollutants there may be a moderate health concern for a very small number of people who are unusually sensitive to air pollution.
AQI: Unhealthy for Sensitive Groups (101 - 150) AQI: Unhealthy for Sensitive Groups (101 - 150)
Although general public is not likely to be affected at this AQI range, people with lung disease, older adults and children are at a greater risk from exposure to ozone, whereas persons with heart and lung disease, older adults and children are at greater risk from the presence of particles in the air.
AQI: Unhealthy (151 - 200) AQI: Unhealthy (151 - 200)
Everyone may begin to experience health effects members of sensitive groups may experience more serious health effects.
 AQI:Very Unhealthy (201 - 300) AQI: Very Unhealthy (201 - 300)
Health alert: everyone may experience more serious health effects.
AQI: Hazardous(301 - 500) AQI: Hazardous (301 - 500)
Health warnings of emergency conditions. The entire population is more likely to be affected.
Action DayAction Day
 
Local Air Quality Resources
Action Day Programs | Forecast
 
State Air Quality Resources
American Lung Association (ALA) of the District of Columbia
District Department of the Environment
District Dept. of the Environment - Contacts
Metropolitan Washington Council of Governments - Air Quality Forecast and Index
Daily AQI
Thursday, June 20, 2013
Particles PM2.5
43 
Good
Particles PM10
11 
Good
Ozone
48 
Good
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Note: data are available beginning August 1, 2010.

Other Information
Current Conditions and Forecasts
Air Quality Maps Archives (by region)