The National Weather Service said extremely cold temperatures and some snow will continue today through the weekend.
Route 422 east of Kittanning had to be closed down last night due to extreme hazardous weather conditions.
The Emergency 9-1-1 Dispatch Center at the request of the Pennsylvania State Police called out two separate fire departments for traffic assistance.
Elderton fire volunteers blocked off traffic in both directions near Muskrat Slide Road.
Kittanning Township fire volunteers closed down traffic in both directions near Dunbar Dip.
PennDOT workers were summoned to treat the road surface. The highway was reopened by 11PM.
Also during the same time period last night, a tractor-trailer truck got stuck near Lenape Heights in Manor Township. The truck was able to continue travel shortly later.
Extreme weather temperatures also delayed the start of school by two hours this morning in the Armstrong School District.