Millions of people have hunkered down against a deep freeze on Christmas Day to ride out the winter storm that has killed at least 29 people across the US.

The storm is expected to claim more lives after trapping some residents inside houses with heaping snow drifts and knocking out power to tens of thousands of homes and businesses.

The scope of the storm has been nearly unprecedented, stretching from the Great Lakes near Canada to the Rio Grande along the border with Mexico.

About 60 per cent of the US population faced some sort of winter weather advisory or warning, and temperatures plummeted drastically below normal from east of the Rocky Mountains to the Appalachians, the National Weather Service said.

Travellers’ weather woes are likely to continue, with hundreds of flight cancellations already and more expected after a bomb cyclone — when atmospheric pressure drops very quickly in a strong storm — developed near the Great Lakes, stirring up blizzard conditions, including heavy winds and snow.

Some 1707 domestic and international flights were cancelled on Sunday as of about 2pm on the east coast, according to the tracking site FlightAware.

The storm unleashed its full fury on Buffalo, with hurricane-force winds and snow causing whiteout conditions, paralysing emergency response efforts.

New York Governor Kathy Hochul said almost every fire truck in the city was stranded Saturday.

Officials said the airport would be shut through Tuesday morning.

The National Weather Service said the snow total at the Buffalo Niagara International Airport stood at 109 centimetres at 7am on Sunday.

Daylight revealed cars nearly covered by 1.8-metre snowdrifts and thousands of houses, some adorned in unlit holiday displays, dark from a lack of power.

With snow swirling down untouched and impassable streets, forecasters warned that an additional 30cm to 60cm of snow was possible in some areas through early Monday morning amid wind gusts of 64km/h.

Source: Associated Press