A week of frigid weather across the United States east of the Rocky Mountains will extend into the start of 2018 as a second arctic air mass ia expected to roll south from Canada across the continent, the National Weather Service says.
New Year's Eve celebrations in Manhattan's Times Square will be bitterly cold, with a forecast for the temperature to fall to minus 12C by midnight, when New York's annual ball drop occurs.
The big night in the Big Apple will be clear, but breezy conditions will make it feel even colder.
Much of the Midwest and north-eastern US has seen daytime highs this week hardly topping minus 10C.
The National Weather Service predicted "another reinforcing shot of arctic air" to slide out from northwestern Canada southeastward on Friday and Saturday. The high-pressure system will "dominate the weather pattern across the US mainland" through the weekend, forecasters said.
The Great Plains and upper Midwest were expected to see weather 15 to 20 degrees below normal, with overnight temperatures below minus 20C in much of the interior region.
New York City was not forecast to see temperatures above freezing until January 8.
Farther south, light snow was expected in Texas and parts of the south-east.
Elsewhere, the southwestern US was getting unseasonably warm weather, while a major winter storm was dropping rain on the Pacific north-west coast and heavy snow Friday and Saturday in the northern Rockies.
