In January, 2003, the eastern two-thirds of the United States was at the mercy of a bitterly cold air mass that has endangered Florida’s citrus trees, choked northern harbors with ice and left bewildered residents of North Carolina’s Outer Banks digging out of up to a foot of snow.
The ice chill deepened as temperatures fell to the single digits in most of the South, with an unfamiliar dip below the freezing mark as far south as parts of interior South Florida. Temperatures in Florida plunged, with West Palm Beach dropping to a record low of 2 degrees.
"We couldn’t believe how cold it was," said Martin King, who arrived this week in Orlando from England. "We brought shorts, T-shirt, and I had to go out and buy another coat. "
The temperature plunge posed a threat to Florida’s US $ 9.1 billion-a-year citrus crop, more of which is still on the trees. Growers were hurrying 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 citrus grower who expected to see damage to oranges and grapefruit at that time.
In Florida, Governor Jeb Bush signed an emergency order to eliminate the weight limit on trucks so citrus growers could get as much fruit to market as possible.
Casey Pace, a spokeswoman for Florida Citrus Mutual, said growers had sprayed trees with sprinklers, which created a layer of ice and helped maintain a temperature near freezing. Citrus trees are considered in danger of damage if the temperature drops below minus 2 degrees Celsius for four hours or more. Snow ranging from a dusting to up to 30 centimeters blanketed the Carolinas, Tennessee and parts of Virginia.

According to the second paragraph, in which area (s) did the temperature fall below zero（）