As wind-chills dipped below zero, Philipsburg-Osceola and Bald Eagle area school districts announced delays of two hours for Friday.
On its website, Bald Eagle Area attributed the delay to a dangerous wind-chill factor.
Northern and western Centre County, northern Clinton County, and Clearfield and Cambria counties were under a wind-chill advisory issued by the National Weather Service.
Temperatures were expected to remain in the single digits Friday, and wind-chill values were forecast to reach as low as -12 degrees in some spots.
Other Centre County public schools had not announced schedule changes by early Friday.