A Code Orange Air Quality Action Day has been issued by the Pennsylvania Department of Environmental Protection (DEP) for Friday, August 6th. The alert covers southeastern counties of Montgomery, Bucks, Chester, Delaware, and Philadelphia, and in the Lehigh Valley-Berks Area, which includes the counties of Berks, Lehigh, and Northampton.

According to the notice, the alert was issued due to a forecast of mostly sunny skies and high temperatures near 90, associated with an area of high pressure that will likely contribute to 8-hour average concentrations of ozone in the Code Orange range.

The U.S. Environmental Protection Agency’s (EPA) Air Quality Index (AQI) provides standardized color codes for forecasting and reporting daily air quality. Green signifies good air quality; Yellow means moderate air quality; Orange represents unhealthy pollution levels for sensitive groups of people; and Red warns of unhealthy pollution levels for all.

An Air Quality Action Day is issued when the AQI is forecasted to be Code Orange or higher. On an Air Quality Action Day, young children, the elderly, and those with respiratory problems, such as asthma, emphysema, and bronchitis, are especially vulnerable to the effects of air pollution and should limit outdoor activities.