Does Niagara Falls ever really freeze over? The answer is yes. During an extended winter cold snap, a hardened crust of ice can accumulate over parts of the falls (the American Falls in particular), creating an amazing, naturally-formed ice sculpture that has been known to reach a thickness of 50 feet.

How Niagara Falls Freezes

Neither the falls nor the river ever freeze solid. Water continues to flow beneath the ice at all times, although it's reduced to a trickle on the rare occasions when ice jams block the river above the falls. Historically, when this blanket of ice has spanned the entire Niagara River, the phenomenon has been known as the "ice bridge." People used to stroll and frolic on and around the frozen falls and even walk across the ice bridge at the base, though no one has been allowed to do the latter since 1912. That year, the bridge broke apart and three tourists died.

As "The Washington Post" wrote, a "frozen" Niagara falls was not an unusual occurrence:

Niagara Falls gets cold every year. The average temperature in Niagara Falls in January is between 16 and 32 degrees. Naturally, it being that cold, ice floes and giant icicles form on the falls, and in the Niagara River above and below the falls, every year. The ice at the base of the falls, called the ice bridge, sometimes gets so thick that people used to build concession stands and walk to Canada on it. It’s nothing out of the ordinary. It is not, to put it bluntly, big polar vortex news.

About the Images of the Frozen Falls

Several photographs, which appear to be authentic, show Niagara Falls frozen on various dates throughout history.

Not all photographs showing the frozen falls are from 1911. There was another historic freeze in March 1848 when the falls actually "went dry" for a few days due to the formation of an ice dam on Lake Erie.

Other photos show Niagara Falls in 1936. "The Washington Post" reported on February 2 of that year that the falls had indeed "frozen dry" for the second time in history.

Another image has been used as a picture postcard, originally hand-tinted, and displayed on the Niagara Falls Public Library website. The card was postmarked August 25, 1911, and bore the following caption:

The cave of the Winds, gyved with a marvelous accumulation of ice and the great flow of water completely hidden by crystalline helmets. Such a sight is rarely to be witnessed, however for history records only three, the last time in 1886, when it is said, a million persons visited Niagara to see the marvelous exhibition of the ice king.

Another frozen falls image, titled "Great Mass of Frozen Spray and Ice-Bound American Falls Niagara," is also from the Niagara Falls Public Library collection, where it is cataloged as a stereo image by Underwood & Underwood. It is dated 1902.

Sources

"Cave of the Winds in Winter Niagara Falls — Details." Niagara Falls Public Library, 2001.

"Great mass of frozen spray and ice-bound American Falls Niagara — Details." Niagara Falls Public Library, 2001.

Mikkelson, David. "Photographs show Niagara Falls frozen in 1911 and 2014." Snopes, January 23, 2007.