The United States east of the Rockies felt more like Siberia Friday morning, as the extremely cold air mass that's been hovering over the country for a week got even colder and moved even farther south.

Temperatures dropped to the single digits in the Carolinas, Florida orange groves froze, northern harbors were choked with ice and a rare snowstorm dumped a foot of snow on the Outer Banks. At least one cold-related death was reported.

A fire at a substation knocked out power to about 31,000 residents around the Raleigh, N.C., suburb of Apex, where the late-morning temperature was 25 degrees, and repairs weren't expected until after nightfall.

"I don't even know what time it is right now," Aimee Allen said. "We're trying to stay in bed."

The cold threatened Florida's $9.1 billion-a-year citrus crop, most of which is still on the trees. Growers hurried to harvest as much of the fruit as possible before it was damaged by cold.

"Time is of the essence in getting fruit to the plant," said Tom Rogers, a Highland City grower who expected to see damage to oranges and grapefruit.

Florida Gov. Jeb Bush signed an emergency order to eliminate the weight limit on trucks so growers could get as much of the fruit to market as possible.

Up the coast, the increasingly icy waters shut down some ferries to Boston and New York, forcing commuters into trains and buses.

The Coast Guard was running icebreaking ships through Massachusetts waters to make way for commercial ships. The Northeast gets the bulk of its home heating oil by water.

Across the South on Friday, temperatures fell to the teens and single digits, with an unfamiliar dip below the freezing mark as far south as interior South Florida.

Record lows for the date included 16 degrees in North Myrtle Beach, S.C., well below the 26 degree mark set in 1991.

Forecasters said temperatures wouldn't get well above freezing until Saturday afternoon.

"This is going to be around all weekend," said Chuck Hansen, public works director for Hickory, N.C.

In West Palm Beach, Fla., the 35-degree reading was also a record, and a combination of cold and wind made it feel like it was in the teens across central Florida.

"We couldn't believe how cold it was," said tourist Martin King, who arrived this week in Orlando, Fla., from Bristol, England. "We brought shorts, T-shirt, and I had to go out and buy another coat."

Schools closed or opened late Friday in many states, including most of North Carolina, Georgia and northern Florida. In some places, roads were clear but officials feared the extreme temperatures.

"If a bus had a mechanical problem, inside that bus would cool up so quick that I wouldn't want to take the risk," said Mike Poole, superintendent in Chattooga County, Ga., which was closed for a second day.

The cold has been linked to at least one death.

In Indiana, the body of a man was found lying in the snow Thursday after he apparently stumbled and fell while walking through the Morgan County fairgrounds. An autopsy was scheduled.

While snow is not uncommon in the North Carolina mountains and the Piedmont, the Outer Banks on Thursday got its first major storm since 1989, with some portions of the barrier islands receiving a record foot of snow.

The drifts attracted sledders to the snow-covered dunes.

"It's not like going to [West Virginia], but it's fun," said contractor Bob McNaughton, a local contractor who zipped on a snowboard near the Wright Brothers National Memorial in Kill Devil Hills. "It beats a workday."

In Columbia, S.C., the tents of Ringling Bros. and Barnum & Bailey Circus were cozy, despite the white flakes.

"The animals look at the change of the weather like kids," said Debbie Fahrenbruck, the show's animal behavioral veterinary technician. "They enjoy it a lot more than adults -- from the elephants down to the pygmy goats."

The Associated Press contributed to this report.