The Pennsylvania Department of Environmental Protection declared a Code Orange Air Quality Action Day for ozone for Thursday, June 20, in Butler County and the surrounding area.

Mostly sunny skies and temperatures in the middle 90’s are expected to create conditions for robust ozone development and formation into the code orange range during the afternoon hours. Any afternoon or evening thunderstorm activity is expected to be isolated in nature, and only affect a small fraction of the area, the DEP said.

The alert also affected Allegheny, Armstrong, Beaver, Butler, Fayette, Washington, and Westmoreland counties.

On air quality action days, 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.

The DEP encourages residents and businesses within the Air Quality Action Day areas are strongly encouraged to voluntarily help reduce air pollution by conserving electricity by setting air conditioning to a higher temperature, combining errands to reduce vehicle trips, limiting engine idling and refueling cars and trucks after dusk.

The U.S. Environmental Protection Agency’s Air Quality Index 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.