Eight people have died so far, as extreme cold pummels the northern United States.

The worst-hit area of Buffalo in New York is buried under almost two metres of snow, with more expected in the next few days.

WBEN radio reporter Randy Bushover told Newstalk ZB's Tim Dower they've now had a year of snow in just three days, but officials hope they can stop the death toll rising any further.

He says four of the eight dead suffered cardiac problems, caused by trying to dig themselves out of the huge snowdrifts.