Children, the elderly and those with respiratory issues should be careful and limit outdoor activity on Saturday, according to the state Department of Environmental Protection.
Most of Southwestern Pennsylvania will be under a code orange designation for ozone, the DEP said.
Orange is the third level of a four-tier air pollution scale, and represents air pollution at a level that could be dangerous for vulnerable groups.
A sunny day with temperatures in the low 90s “will create robust ozone formation,” the DEP announced Friday.
The code orange alert affects Allegheny, Armstrong, Beaver, Butler, Fayette, Washington, and Westmoreland counties.
All residents are asked to limit air pollution by lowering their air conditioning, minimizing driving, and waiting until after dusk to refuel cars and trucks.
The last code orange alert affecting the region was issued July 9.
