Northwest winds that persisted into the morning of the 13th combined with an arctic air mass to produce wind chill factors as low as around 25 degrees below zero in the Poconos and 10 to 15 degrees below zero elsewhere in Eastern Pennsylvania. Actual morning low temperatures were in the positive single numbers, except for some below zero minimums in the Poconos.  Advisory level wind chills persisted through the morning in the Poconos. Many counties and municipalities declared Code Blues.
The lowest hourly wind chill factors included 27 degrees below zero in Mount Pocono (Monroe County), 15 degrees below zero at the Lehigh Valley International Airport, 14 degrees below zero in Doylestown (Bucks County), 12 degrees below zero in Coatesville (Chester County), Pottstown (Montgomery County) and Reading (Berks County) and 9 degrees below zero at the Philadelphia International Airport.
Actual morning low temperatures included 4 degrees below zero in Mount Pocono, 4 degrees above zero in Doylestown (Bucks County) and Nazareth (Northampton County), 5 degrees above zero at the Lehigh Valley International Airport and Perkasie (Bucks County), 6 degrees above zero in Reading (Berks County) and Pottstown (Montgomery County), 7 degrees above zero in Saint Davids (Delaware County) and Horsham (Montgomery County), 9 degrees above zero in Coatesville and Kennett Square (Chester County) and 10 degrees above zero at the Philadelphia International Airport.  The arctic high pressure system moved southeast from North Dakota early on the 12th into the central Mississippi Valley on the evening of the 12th and into the Ohio Valley on the morning of the 13th.

Cold/Wind Chill in UPPER BUCKS, PENNSYLVANIA
From 13-FEB-15 01:00:00 to 13-FEB-15 09:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Cold/Wind Chill in PHILADELPHIA, PENNSYLVANIA
From 13-FEB-15 04:00:00 to 13-FEB-15 07:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

Cold/Wind Chill in EASTERN MONTGOMERY, PENNSYLVANIA
From 13-FEB-15 03:00:00 to 13-FEB-15 08:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Cold/Wind Chill in NORTHAMPTON, PENNSYLVANIA
From 13-FEB-15 01:00:00 to 13-FEB-15 08:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Cold/Wind Chill in DELAWARE, PENNSYLVANIA
From 13-FEB-15 04:00:00 to 13-FEB-15 07:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Cold/Wind Chill in EASTERN CHESTER, PENNSYLVANIA
From 13-FEB-15 02:00:00 to 13-FEB-15 09:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Extreme Cold/Wind Chill in CARBON, PENNSYLVANIA
From 13-FEB-15 01:00:00 to 13-FEB-15 09:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

Extreme Cold/Wind Chill in MONROE, PENNSYLVANIA
From 13-FEB-15 01:00:00 to 13-FEB-15 09:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

Cold/Wind Chill in WESTERN CHESTER, PENNSYLVANIA
From 13-FEB-15 02:00:00 to 13-FEB-15 09:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: AWOS

Cold/Wind Chill in BERKS, PENNSYLVANIA
From 13-FEB-15 02:00:00 to 13-FEB-15 08:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

Cold/Wind Chill in LEHIGH, PENNSYLVANIA
From 13-FEB-15 01:00:00 to 13-FEB-15 08:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

Cold/Wind Chill in LOWER BUCKS, PENNSYLVANIA
From 13-FEB-15 01:00:00 to 13-FEB-15 09:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

Cold/Wind Chill in WESTERN MONTGOMERY, PENNSYLVANIA
From 13-FEB-15 03:00:00 to 13-FEB-15 08:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS