One of the harshest arctic outbreaks in years occurred in Eastern Pennsylvania on the 7th.  Record calendar day low temperatures occurred and combined with strong northwest winds produced wind chill factors as low as around 30 degrees below zero in the Poconos and around 20 degrees below zero elsewhere. High temperatures struggled to get above zero in the Poconos and reach double digit figures elsewhere. The excessive cold  caused many schools and universities to either cancel classes or have delayed openings.
The severe cold led to Pennsylvania Governor Tom Corbett signed a Proclamation of Propane and Heating Oil Emergency��� to waive federal and state motor carrier regulations related to hours of service for drivers of commercial motor vehicles transporting propane gas and heating oil in Pennsylvania. AAA Mid-Atlantic reported an 81 percent increase in service calls, mainly for dead batteries. Amtrak reported extensive delays in its rail service. The cold weather also affected SEPTA Regional Rail service in the Philadelphia area as there were delays on the Paoli/Thorndale line. The cold weather strained power supplies. PJM Interconnection, the agency that oversees the electric grid supplying the region, said electricity suppliers were struggling to keep up with surging demand as the cold forced some power plants to shut. An all-time winter record usage was recorded at 8 a.m. EST on the 7th, 138,600 megawatts surpassing the previous record from 2007. Utilities asked their customers where possible to switch to diesel or fuel oil.  Three thousand homeless people in Philadelphia were sheltered.

The low temperature of 4 degrees above zero at the Philadelphia International Airport was the coldest of the winter and the coldest air temperature day since January 24, 2005 when the low reached 3 degrees above zero. The low temperature of zero at Reading (Berks County) was the coldest of the winter season and matched the low last set on January 24, 2011. The low temperatures of 8 degrees below zero in Mount Pocono (Monroe County) and one degree below zero at the Lehigh Valley International Airport were higher than the morning of January 4th.
Other actual low temperatures included 3 degrees below zero in Lehighton (Carbon County) and Fleetwood (Berks County), 2 degrees below zero in East Stroudsburg (Monroe County), Glenmoore (Chester County) and Macungie (Lehigh County), 1 degree below zero in Easton (Northampton County), zero in West Chester (Chester County) and Perkasie (Bucks County), 1 degree above zero in Newtown Square (Delaware County) and Pottstown (Montgomery County), 2 degrees above zero in Horsham (Montgomery County) and 3 degrees above zero in Langhorne (Bucks County).
Lowest hourly wind chill factors included (they all occurred during the morning of the 7th) 32 degrees below zero in Mount Pocono (Monroe County), 23 degrees below zero at the Lehigh Valley International Airport, 22 degrees below zero in Doylestown (Bucks County) 21 degrees below zero in Reading (Berks County) and Coatesville (Chester County) and 18 degrees below zero at the Philadelphia International Airport.

Extreme Cold/Wind Chill in CARBON, PENNSYLVANIA
From 07-JAN-14 02:00:00 to 07-JAN-14 20:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

Cold/Wind Chill in NORTHAMPTON, PENNSYLVANIA
From 07-JAN-14 02:00:00 to 07-JAN-14 14:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

Cold/Wind Chill in UPPER BUCKS, PENNSYLVANIA
From 07-JAN-14 02:00:00 to 07-JAN-14 13:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

Cold/Wind Chill in WESTERN MONTGOMERY, PENNSYLVANIA
From 07-JAN-14 02:00:00 to 07-JAN-14 13:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

Cold/Wind Chill in WESTERN CHESTER, PENNSYLVANIA
From 07-JAN-14 02:00:00 to 07-JAN-14 13:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: AWOS

Cold/Wind Chill in EASTERN CHESTER, PENNSYLVANIA
From 07-JAN-14 03:00:00 to 07-JAN-14 12:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Cold/Wind Chill in EASTERN MONTGOMERY, PENNSYLVANIA
From 07-JAN-14 03:00:00 to 07-JAN-14 12:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: AWOS

Cold/Wind Chill in LOWER BUCKS, PENNSYLVANIA
From 07-JAN-14 02:00:00 to 07-JAN-14 12:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Cold/Wind Chill in DELAWARE, PENNSYLVANIA
From 07-JAN-14 03:00:00 to 07-JAN-14 11:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

Cold/Wind Chill in PHILADELPHIA, PENNSYLVANIA
From 07-JAN-14 03:00:00 to 07-JAN-14 11:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

Extreme Cold/Wind Chill in MONROE, PENNSYLVANIA
From 07-JAN-14 02:00:00 to 07-JAN-14 20:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

Cold/Wind Chill in BERKS, PENNSYLVANIA
From 07-JAN-14 01:00:00 to 07-JAN-14 13:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

Cold/Wind Chill in LEHIGH, PENNSYLVANIA
From 07-JAN-14 02:00:00 to 07-JAN-14 14:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS