An unprecedented cold front has frozen parts of Niagara Falls, pictured above, drawing tourists to document the rare event.

Snow and ice coat coin-operated viewers at Niagara Falls.
© AP Photo / Carolyn Thompson
At Letchworth State Park in western New York, the arctic freeze has transformed a pressure-fed fountain in to a five-story-tall “ice volvano.”
— Good Morning America (@GMA) February 18, 2015
In the Midwest, the Great Lakes are now more than 85% iced over, according to the Great Lakes Environmental Research Laboratory, with Lake Erie leading the way at more than 98%.

Lake Erie from the deck of the Coast Guard Cutter Bristol Bay
© AP Photo / U.S. Coast Guard, Lt. Cmdr. John Henry

Snow coats Navy Pier surrounded by ice-covered Lake Michigan in Chicago.
© AP Photo / Kiichiro Sato
Arctic air and bitterly cold wind is moving across the Northeast, plunging temperatures into record low single digits, accompanied by subzero wind chills.

Ice flows pass through New York Harbor.
© AP Photo / John Minchillo

Ice collects on the Delaware River in view of Philadelphia.
© AP Photo / Matt Rourke

