Plummeting temperatures in the US and Canada have caused chaos for many but have created a spectacular sight at Niagara Falls.
Niagara Falls hasn’t frozen over, but it has become an icy spectacle, thanks to a blast of arctic wind and cold that blew around and froze the mist on surfaces and landscaping.
Despite the urban legends, Niagara Falls doesn’t freeze solid in the winter, tourism officials say.
Plummeting temperatures in the US and Canada have caused chaos for many but have created a spectacular sight at Niagara Falls
However, a section of the American Falls, one of three waterfalls that make up the natural attraction, has frozen. The Niagara River rapids and larger Horseshoe Falls continue to flow unimpeded.
Visitors who normally see a thundering waterfall have travelled to see part of the cascades frozen solid.
A polar vortex hitting North America is now heading toward East, ushering in dangerous temperatures not seen in two decades, warn forecasters.
From Montana to Maryland, about half of the population has been placed under a wind chill warning or advisory.
In Canada, the province of Ontario is facing temperatures of -40C (-40F) with wind chill.
Thousands of flights have been grounded, and residents told their skin could freeze if they go outside.
People on the North East coast were warned to prepare themselves for the cold front sweeping in on Tuesday from the Midwest.
Temperatures were set to plummet overnight in New York and Washington DC by as much as 45 degrees, from unseasonably clement highs a day earlier.
New York Governor Andrew Cuomo announced that parts of major highways would be closed in preparation for the extreme weather, which could see the mercury plummet to -26C (-15F) overnight with wind chill.
The polar blast was threatening crops and livestock across the American farm belt, even in the usually temperate Deep South.
The sub-zero snap was expected to reach as far south as Texas and central Florida, the National Weather Service said.
Tennessee and Kentucky were forecast to receive several inches of snow.
From Montana to Maryland, about half of the population has been placed under a wind chill warning or advisory
The weather has been blamed for at least 16 deaths in recent days.
Meteorologists said some 187 million people in all would be able to feel the effects of the cold snap by Tuesday.
It has been widely blamed on a shift in the weather pattern known as the “polar vortex”.
In Comertown, Montana, on Monday the temperature sank to -53C (-63F) with wind chill.
The state of Minnesota saw the mercury plummet to -48C (-56F) by the same measure.
The South Pole, and Irkutsk, Siberia, by comparison, jointly basked in a relatively balmy -33C.
More than 4,500 flights were cancelled just on Monday in the US because of the extreme weather.
JetBlue Airways suspended nearly all operations at airports in Boston and around New York City until midday on Tuesday.
The state of Minnesota and the city of Chicago, Illinois, have ordered all schools closed.
It was so cold that even the polar bear at Chicago’s Lincoln Park Zoo was kept indoors, CNN reports.
Public parks were also shut as officials warned that exposed flesh could become frostbitten.
In Illinois, the National Guard used 10-tonne military vehicles to clear up after several lorries jackknifed, stranding nearly 400 vehicles. There were no fatalities or injuries reported in those incidents.
Freezing rain also caused hundreds of flight cancellations at airports in Toronto and Ottawa.
Nearly 1,000 homes in Newfoundland, Canada, were still without electricity on Monday after a power outage.
The Northeast and Upper Midwest are braced for potentially record-breaking low temperatures as a “polar vortex” brings more freezing weather.
A winter storm has already blanketed areas of Canada and the north-eastern US with up to 2ft of snow.
The snow storm has been blamed for 16 deaths in recent days and the cancellation of more than 3,700 flights this weekend.
Schools in Chicago are among those closing as officials tell people to stay indoors on Monday.
Meanwhile, a plane from Toronto slid into snow as it turned onto a taxiway after landing at New York’s JFK airport on Sunday.
No-one was hurt in the incident but all flights at the airport were suspended for two hours because of icy runways.
The plunging temperatures result from the polar vortex, an anti-clockwise pool of cold, dense air.
Forecasters say temperatures in the north and central US could feel as low as -60F (-51C) with the effect of wind chill.
Authorities have warned residents to remain indoors, both for their own safety and to keep roads clear for snow removal.
The Northeast and Upper Midwest are braced for potentially record-breaking low temperatures as a “polar vortex” brings more freezing weather
In Canada, thousands of people on the island of Newfoundland remain without power due to a transformer fire linked to heavy snow.
“The coldest weather in years will be making its presence known from the Upper Midwest to the Mid-Atlantic region for the beginning of the work week,” the US National Weather Service said in a statement.
The states of Ohio, South Dakota and Illinois are among those set to be hit. Tennessee and Kentucky are forecast to see several inches of snow.
The weather service said “an incredibly strong surge of bitterly cold Arctic air” was sweeping across the country until Tuesday.
It is set to continue to the north-east, where residents are still digging out from the week’s deadly snowstorm.
It could bring some of the coldest temperatures in two decades.
In Canada, the temperature dropped as low as -20F (-29C) in Toronto and -36F (-38C) in Quebec City with wind chill on Thursday – the lowest seen in at least two decades there.
Heavy snow has also affected US states including New York, Connecticut and Massachusetts. Boston was said to be the worst hit with nearly 18 in of snow.
Schools have also been closed across the state of Minnesota for Monday, as well as for parts of Wisconsin, Illinois and Indiana, among others.
Officials in Chicago, Illinois reversed a decision to keep schools open following criticism from a teachers’ union, according to the Associated Press.
State offices were to stay closed in neighboring Indiana where a state of emergency was declared in Lake County in the northwest, allowing only emergency or law enforcement vehicles on the roads.
The Green Bay Packers football team handed out hot chocolate and hand warmers to fans at a game being played in Wisconsin on Sunday. Doctors had urged fans to wear at least three layers of clothing.
Sixteen deaths have been blamed on the wide-ranging storm, according to the Associated Press news agency.