PENNSYLVANIA - While Pennsylvania experiences all four seasons, its winters can occasionally turn brutal, driven by Arctic blasts that transform the rolling hills of the Keystone State into a frozen tundra. If you think today is chilly, it pales in comparison to the deepest freeze in the State history.
The Coldest Temperature Ever Recorded In Pennsylvania was a staggering −42°F.
The Record-Breaking Day
The record was set on January 5, 1904, in the small borough of Smethport, located in McKean County.
Situated in the northern tier of the state near the Allegheny National Forest, Smethport is part of a region often referred to as the "Icebox of Pennsylvania." Its geographic location in a high-elevation valley makes it the perfect vessel for "cold air drainage," where dense, frigid air settles into the basin on clear, calm nights.
The "Icebox" Conditions
To understand how Pennsylvania hit, several meteorological factors had to align:
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Arctic Air Mass: A powerful polar vortex had descended deep into the Northeastern United States.
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Snow Cover: Heavy snow on the ground acted as an insulator, reflecting any daytime heat into the atmosphere and allowing the surface to cool rapidly at night.
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Clear Skies: Without cloud cover to trap heat, "radiational cooling" allowed temperatures to plummet far below zero after the sun went down.
How Does It Compare?
To put into perspective, Pennsylvania’s record is significantly colder than the record lows of many cities across the state:
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Philadelphia: The city’s all-time low is (set in 1934).
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Pittsburgh: The Steel City’s record is (set in 1994).
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State College: The home of Penn State hit its record of in 1899.
While Smethport holds the official state record, it isn't a one-hit wonder. In January 1994, during a legendary cold snap, the town of Kane (also in McKean County) reportedly neared the record with temperatures hitting .
Living Through the Deep Freeze
In 1904, life was very different. Residents in Smethport didn't have modern HVAC systems or high-tech insulation. Keeping a home warm meant constant tending to coal stoves and wood fires. Steam pipes frequently burst, and transportation—largely reliant on horses and early rail—came to a grinding halt as lubricants froze solid.
Where is the "Icebox" Today?
Smethport still embraces its chilly heritage. If you visit today, you’ll find local markers proudly proclaiming it the home of the coldest recorded temperature in the state. Even in the height of summer, nighttime temperatures in this valley can be surprisingly brisk compared to the humidity of Philadelphia or Harrisburg.
