Freeze Warnings are now in effect for most of Pennsylvania from 1 a.m. to 9 a.m. EDT Sunday, with lows between 25 and 30 degrees expected in central Pennsylvania.
The earlier Freeze Watches have been upgraded to warnings.
A warning means sub-freezing temperatures are expected, not just possible.
Five National Weather Service offices cover the state.
Frost and freeze conditions could kill crops and other sensitive vegetation.
Unprotected outdoor plumbing could also be damaged.
Source: NWS State College on X
Central Pennsylvania
NWS State College expects sub-freezing temperatures between 25 and 30 degrees.
The warning covers most of central Pennsylvania.
Valley locations and sheltered rural areas will be the coldest.
Cities include Harrisburg, Lancaster, York, State College, Altoona, Johnstown, Williamsport, Gettysburg, Chambersburg, Carlisle, Lebanon, Hershey, Bloomsburg, Sunbury and Lewistown.
It also covers Huntingdon, Bedford, Somerset, Clearfield, DuBois, St. Marys, Warren, Wellsboro and Coudersport.
The earlier watch skipped McKean County, where a freeze has already occurred this autumn.
Western Pennsylvania
NWS Pittsburgh expects lows in the upper 20s to around 30.
The warning covers western Pennsylvania, plus east central Ohio and northern West Virginia.
Pennsylvania counties include Allegheny, Beaver, Butler, Armstrong, Washington, Greene, Westmoreland, Fayette, Indiana, Lawrence, Mercer, Venango, Clarion, Jefferson and Forest.
Cities include Pittsburgh, Washington, Butler, Greensburg, Uniontown, Latrobe, Kittanning, Indiana, Punxsutawney, Oil City, New Castle and Beaver Falls.
Northwest Pennsylvania
NWS Cleveland expects lows as low as 30 degrees.
The Pennsylvania part of the warning covers Crawford and Southern Erie counties.
Cities include Meadville, Titusville, Edinboro, Corry and Union City.
Northeast Pennsylvania
NWS Binghamton expects lows as low as 28 degrees.
The warning covers Lackawanna and Luzerne counties.
Cities include Scranton, Wilkes-Barre and Hazleton.
NWS Mount Holly expects lows as low as 28 degrees in Carbon and Monroe counties.
Cities include Stroudsburg and Jim Thorpe.
Eastern Pennsylvania
NWS Mount Holly expects lows as low as 31 degrees.
The warning covers Berks, Lehigh, Northampton, Upper Bucks, Western Chester and Western Montgomery counties.
Cities include Allentown, Bethlehem, Easton, Reading, Pottstown, Perkasie and Oxford.
The same warning covers Morris, Warren and Hunterdon counties in New Jersey.
How to Prepare
A Freeze Warning means sub-freezing temperatures are expected.
Cover or bring in potted plants and tender vegetation before Saturday night.
Harvest any remaining crops that can be picked.
Protect exposed outdoor plumbing, such as hose bibs and irrigation lines.
Local forecasts and alerts: NWS State College and NWS Pittsburgh.
For more on freezes and plant damage, see the NWS Cold Weather Safety guide.
