Call it a “cold spell” or an “arctic freeze,” one thing is for sure: the polar vortex was truly, excruciatingly, cold.

Beginning on January 2^nd, a large part of the United States and Canada experienced record low temperatures. January 6^th brought the coldest average temperature nationwide in the 21^st century. On January 7^th, Chicago was actually colder then the south pole at the same time.

Many areas experienced subzero temperatures for multiple days. With wind chill, temperatures in some areas crept as low as -30F or even colder. On January 4^th, Albany experienced a recorded low temperature of a glacial -12F, without accounting for the bitter wind chill.

Most meteorologists agree that this drop in temperatures was caused by the “polar vortex.” The polar vortex is a term that meteorologists use to refer to a semi-permanent area of low pressure in the upper atmosphere above the north and south poles.

The polar vortex is strongest in the winter when the difference in temperature between the poles and the equators is greatest. The recent bitter cold temperatures were a result of this polar vortex moving further south than it usually is, bringing with it temperatures typically reserved to the arctic.

Some scientists believe this weather phenomenon to be part of climate change (commonly referred to as Global Warming) caused by the emission of greenhouse gasses. It is possible that the heating of the arctic caused the temporary movement of the polar vortex southward.

Other studies have linked extreme temperatures, both hot and cold, to climate change. Based on current scientific data however, the hypothesis that the polar vortex was caused by climate change is hard to prove, and until then is just a theory.

Financially, the polar vortex had a relatively small impact on the US economy as a whole. Overall, economists consider the polar vortex to have cost roughly $5 billion, miniscule compared to the $17 trillion dollar US economy.

There were hundreds of cancelled airline flights, accounting for close to $1.4 billion in lost value. Lost productivity, higher heating bills, decreased consumer spending, and halting of construction projects also contributed to the economic hit.

Whatever the cause, and whatever the impact, the polar vortex caused some of the most frigid temperatures in recent memory.