Pennsylvania wakes up to a sharp, biting chill, with frost clinging to grass and windshields across central valleys as temperatures hover near freezing.
According to the National Weather Service, a Frost Advisory remains in effect until 8 a.m., with lows near 34°F impacting State College, Altoona, Williamsport, Lock Haven, and Bedford.
This is part of a broader system dragging colder-than-normal air into the Mid-Atlantic, creating repeated frost risks through the weekend.
The immediate impact is on vegetation. Sensitive plants, early gardens, and flowering trees face damage if left uncovered. In rural valleys and low-lying areas near State College, temperatures can briefly dip below freezing, increasing the risk of plant loss.
Travel impacts are minor but noticeable. Early drivers along I-99 and Route 322 may encounter patchy frost on bridges and shaded stretches, especially where moisture settled overnight. Reduced tire grip is possible in colder pockets.
Conditions shift quickly by late morning. Sunshine helps temperatures rebound into the upper 50s, though the air remains crisp. Rain develops later today, bringing wet pavement and reduced visibility for the evening commute in State College and nearby corridors.
A secondary frost window returns late tonight into early Saturday, with another round of near-freezing temperatures likely across central Pennsylvania.
Five-day outlook:
Saturday: Early frost, then partly sunny, high near 56°F
Sunday: Frost early, then mostly sunny, high near 56°F
Monday: Milder, high near 67°F
Tuesday: Showers possible, high near 74°F
Wednesday: Periods of rain, high near upper 60s
