In the winter of 1911, Niagara Falls transformed into a surreal spectacle as a brutal cold snap turned the thundering cascade into an icy marvel. Temperatures plummeted for weeks, encasing the falls and surrounding landscape in thick layers of ice, creating the rare illusion that Niagara had frozen solid. Visitors flocked to witness the extraordinary sight, still remembered as one of the most dramatic freezes in the waterfall’s history.

Niagara doesn’t freeze (technically)

Niagara Falls, formed around 12,000 years ago at the end of the last Ice Age, was sculpted by melting glaciers. The water from the Great Lakes began to flow over the Niagara Escarpment, a steep cliff of ancient rock, gradually eroding the bedrock and forming the gorge and the three iconic waterfalls: Horseshoe Falls, American Falls, and Bridal Veil Falls.

Contrary to some claims, Niagara Falls doesn’t freeze completely. Water freezes at 32°F (0°C), but due to the sheer volume and motion of the water, it would require temperatures much lower—around 14°F (-10°C) or colder for an extended period. With around 168,000 cubic meters of water (the equivalent of a million bathtubs) flowing per minute, the force and volume make it impossible for the falls to freeze solid.

The volume of water is absolutely monstrous: around 168,000 cubic meters (or one million bathtubs) per minute. This immense volume makes the flow far too strong to solidify entirely.

Even as parts of Niagara freeze, the river beneath the falls keeps flowing. In most cases, the water beneath the ice continues to flow steadily, as the constant movement of the river helps prevent it from freezing completely. The flow of water from the falls also stirs the river, keeping it from becoming still enough for ice to completely take over.

However, in particularly severe winters, thick layers of ice can form on the surface of the river, creating what is known as an “ice bridge.” This phenomenon has been known to stretch across the river, linking the Canadian and American sides. These bridges were so stable in the past that people would cross them on foot.

In fact, up until 1912, tourists were allowed to walk across these ice bridges, sometimes setting up booths and even playing sports on the frozen river. However, after a tragic incident in which the ice collapsed, the practice was banned.

Why Niagara sometimes appears to freeze

However, under specific conditions, the water’s surface can freeze, and ice can accumulate around the falls and on the rocks, creating the impression that Niagara has come to a halt.

For this to happen and Niagara Falls to partially freeze, a few specific weather conditions need to align. First and foremost, temperatures need to plummet well below freezing and remain that way for an extended period. Typically, the mercury must stay around or below 14°F (-10°C) for several days or weeks for noticeable freezing to occur.

Cold temperatures cause the mist and water droplets from the falls to crystallize in the air. This mist is a result of the waterfall’s force, which sends fine sprays of water into the atmosphere. As the cold air circulates, these droplets freeze on contact, attaching themselves to nearby structures, plants, and rocks. The more prolonged the cold snap, the greater the accumulation of ice.

If strong winds blow the mist in one direction, ice will build up on one side of the falls more heavily than the other. This is why in some winters, you’ll see thick layers of ice on the American Falls while Horseshoe Falls remains relatively clear.

As ice builds up, it can create spectacular scenes of snow and ice formations, giving the illusion that Niagara is frozen solid. These ice formations are particularly thick at the base of the falls, where the cold air is even more trapped.

The one time a part of Niagara completely froze

The only time the river and falls actually froze was on March 29, 1848. This was still not technically a full freeze — it was an ice jam that blocked the flow of the river for around 40 hours. Waterwheels stopped, and mills and factories shut down for having no power. 

In 1912, American Falls was also completely frozen. Though smaller than the neighboring Horseshoe Falls, which sits on the Canadian side, the American Falls is still an impressive sight, with a height of about 90 to 100 feet and a width of around 950 feet.

It’s not uncommon for Niagara to freeze partially. During some winters, the ice sheet got as thick as 40 to 100 feet (12 to 30 m), though that thickness was not reached since 1954. The ice bridge of 1841 was said to be over 100 feet thick, though this was not proven.

The years 1885, 1902, 1906, 1911, 1932, 1936, 2014, 2017 and 2019 are noted for partial freezing of the falls.

Climate change and the future of a frozen Niagara

In recent years, the frequency and intensity of these freezes have diminished, thanks in part to global climate change. Warmer winters mean fewer sustained cold snaps and less opportunity for the extreme conditions that lead to large-scale ice formation.

Historically, Niagara Falls would freeze every few years during particularly harsh winters. The most famous of these freezes occurred in 1848 when an ice blockage on Lake Erie reduced the water flow so dramatically that Niagara Falls appeared to completely stop for almost 30 hours. But as temperatures continue to rise globally, such dramatic events may become increasingly rare.

The phenomenon of Niagara Falls freezing might also be impacted by the increasing unpredictability of weather patterns due to climate change. While we may still see intermittent freezing in the future, the conditions needed to create these breathtaking ice formations may become less common.

Just because average temperatures are increasing doesn’t mean Niagara won’t “freeze” again — cold spells still happen. But even though the ice can reach impressive thicknesses, it rarely stops the flow of water entirely. Instead, the falls continue to thunder beneath the surface, unseen but unfrozen.