A haze and a light smell of smoke are expected to blanket the area Tuesday night and Wednesday.
The National Weather Service said an Air Quality Alert has been issued through Wednesday in Bucks County and Hunderton County.
“Sensitive groups should take precautions if going outdoors!” forecasters said.
The haze and possible smell are an effect of the wildfires raging in Nova Scotia, Canada. The smoke from the fires is blowing into the U.S.
The National Weather Service confirmed the presence of smoke in parts of New England Tuesday morning.
The smoky haze comes just one week after smoke from wildfires in Alberta, Canada caused an evening haze in front of the sun.
The wildfires in Nova Scotia have burned tens of thousands of acres.
The fires have caused thousands of people to flee their homes and damaged hundreds of structures, officials have said.
CBC News, a Canadian news network, reported that crews on the ground and in the air are battling the flames, but weather conditions were not helping.