The Great Lakes of the Midwest United States are almost completely frozen for the first time in two decades.
The BBC reports they are currently 88 percent covered with ice. The last time the ice was so extensive was 94 percent in 1994.
The latest snow storm on the Atlantic coast is now blamed for the deaths of more than two dozen people.
More than 440,000 households were still without electricity by Friday morning, mainly in Georgia and South Carolina, down from 1.2 million.
Road conditions were still treacherous: 30 people were injured, five severely, in a multiple pile-up near Philadelphia on Friday morning. The crash spawned a traffic jam stretching for 8km.
Many schools remained closed in eight states from Virginia to Maine, while the federal government in Washington DC opened two hours late after closing completely on Thursday.
The BBC reports almost 1500 flights were cancelled on Friday, compared with 6500 the day earlier. All flights were grounded at Ronald Reagan Washington National Airport on Thursday.
Doctors are trying to save the baby of an expectant woman who was killed by a snow plough in New York.
Min Lin, 36, died after being struck on Thursday by a snow plough as it reversed outside a shopping centre in Brooklyn.
She was taken to a hospital, where her baby, which was nearly full-term and weighed 6lb 6oz, was delivered by caesarean section.
The BBC reports the child is in a critical condition in a neonatal intensive care unit.