Temperatures in the US are 11 to 17 Celsius below normal and icy water is the last place most people would want to be.
But while dangerously low temperatures enveloped much of the Midwest, they didn't deter hundreds of people from marking the new year by jumping into Lake Michigan. Despite a warning of potential hypothermia from the local fire chief, throngs of people took part.
A similar event was cancelled from the Chicago lakefront, where the temperature dipped below zero, after organisers said the lake was too dangerous. Instead, would-be plungers had their pictures taken while jumping on the frozen beach — in their swimsuits.
The sky was sunny and the water was freezing at Coney Island, where several hundred people ran into the ocean. The Polar Plunge has been a New York tradition since 1903. "It started on my bucket list. It's a rush, a shock. It'll wake you up," said Louie Forte, 65, of Brooklyn, who took part in his seventh plunge. "This year is the coldest year yet."
With the temperature at -8C some said the water was warmer, at 3C.