WASHINGTON - US President Donald Trump on Thursday (Dec 28) made light of climate change science as an Arctic chill settled on much of the central and northeastern United States and Canada, forcing people indoors, stranding motorists with dead car batteries and complicating firefighting duties.
In the United States, the National Weather Service said that "dangerously cold temperatures and wind chills" were pummelling much of the central and eastern part of the country.
"In the East, it could be the COLDEST New Year's Eve on record," Mr Trump tweeted from his Mar a Lago resort in Florida, where he is on holiday vacation.
"Perhaps we could use a little bit of that good old Global Warming that our Country, but not other countries, was going to pay TRILLIONS OF DOLLARS to protect against. Bundle up!"
In New York, Governor Andrew Cuomo earlier warned residents to prepare for "dangerously cold weather", with below-normal temperatures expected to be between minus 12.7 deg C and minus 6.6 deg C through Saturday.
Mr Trump's missive quickly drew Twitter eye-rolls from many users exasperated that the Republican US president could use cold weather to mock the science behind climate change.
"Weather is not the same as climate," tweeted Representative Pramila Jayapal of Washington state. "The president should be able to understand that. It isn't hard."
Dr Jonathan Foley, executive director of the California Academy of Sciences, wrote: "Believe it or not, global climate change is very real even if it's cold outside Trump Tower right now."
"Just like there is still hunger in the world, even if you just had a Big Mac."
The Washington Post's Capital Weather Gang on Wednesday had tweeted: "US to be coldest region in world relative to normal over next week."
"Please note rest of world will be much warmer than normal lest anyone try to claim pocket of cold in US debunks global warming, which they will invariably and irresponsibly do," the weather reporters said.
Mr Trump, 71, has dismissed global warming as a Chinese hoax, vowed to quit the 2015 Paris accord and tapped fossil fuel allies to key environmental posts.
His administration also dropped climate change from the list of national security threats.
In Canada, firefighters saw water at times freeze in their hoses as they battled an overnight blaze south of Montreal, in Quebec province.
Environment Canada increased the number of extreme cold warnings around the country, bulletins issued only when the cold "creates an elevated risk to health such as frost bite and hypothermia".
On Thursday morning, the thermometer plunged to minus 40 deg C in Geraldton, in northern Ontario province.
"And that's not considering the wind chill factor," said meteorologist Alexandre Parent with Environment Canada.
"We have to go back in 1993 to see this kind of weather in Ontario and Quebec," he said.
Ice crystals fell in the northwestern city of Whitehorse when rain fell amid freezing wind.
The Arctic temperatures are expected to last into early 2018, Environment Canada said.
Health Canada warned that exposed skin could freeze in less than 10 minutes in places where temperatures were approaching minus 35 deg C.
Canadian homeless shelters struggled to keep up with the demand for services and issued special appeals for donations of warm clothes.
This month's cold wave caps a year that saw ferocious hurricanes, heat waves, floods and wildfires wreak global havoc.