'Polar Vortex' Brings Extreme Cold To United States

Leo Lajqi blows snow off a sidewalk at the end of a snow storm in Brooklyn, New York.

A plow pushes snow in New York's Times Square. The governors of New York and New Jersey declared a state of emergency and urged residents to stay indoors as a major storm struck on January 2.

Children throw snowballs in New York's Central Park on January 3, after a winter storm called "Hercules" struck the Northeast.

Travelers leave a train station in Boston, Massachusetts, where nearly two feet (60 centimeters) of snow fell in some areas.

Ice and slush cover the road in Scituate, Massachusetts. The severe weather temporarily delayed flights and forced schools and government offices to close.

Waves crash into houses in Scituate, Massachusetts, during a storm on January 3.

Snow is piled high in front of a Home Depot store in Boston, Massachusetts.

A man photographs the Korean War Veterans Memorial under a layer of snow in Washington, D.C..

Hannah Beil (right) learns to ice skate as her sister Kendall practices hockey on a frozen pond in Northfield, Illinois, as temperatures hover near 0 degrees Fahrenheit (-17.7 degrees Celsius).

Icicles hang from the eaves of a house as temperatures sank to 0 degrees Fahrenheit (-17.7 C) in Wilmette, Illinois.

Surfers trudge through snow to reach the shore in Rockaway Beach, New York.

Kyona, a rescue dog from Japan, wears booties in a New York City park after an overnight snowfall.

People go sledding Prospect Park in New York's Brooklyn borough after a snowstorm.