A blast of cold air brought flurries to the Sunshine State on Thursday but seemed to have spared citrus crops from the major damage that growers had feared.

A serious freeze would have been devastating to the country's biggest citrus industry, already struggling from years of diseases and hurricanes. But most orange and grapefruit groves are in Central and South Florida, where temperatures hovered in high 20s and low 30s. Trees can be ruined when temperatures fall to 28 degrees for four hours.

"Mother Nature cut us a break this time and now we can continue to produce the quality citrus crop Florida is known for," said Michael W. Sparks, executive vice president and CEO of grower advocacy group Florida Citrus Mutual.

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Temperatures were not below freezing for long enough to cause widespread damage to Florida's citrus trees, the group said. In fact, the cold could benefit some growers because it slows down growth and hardens up citrus trees.

Orange juice futures for immediate delivery fell slightly in early trading Thursday on the New York Board of Trade.

Growers had tried to harvest as many mature fruits and vegetables as possible, and tried to protect plants by spraying them with water that freezes, insulating the temperature at 32.

Temperatures in many areas of northern Florida dropped into the 20s early Thursday, following the 30-degree temperatures some northern parts of the state saw Wednesday. Cross City was at 20. Farther south, Orlando was 31 and it was 39 in Miami. Snow flurries were reported near the Daytona Beach coastline, the first in Florida since 2006.

People in the Northeast, mid-Atlantic, the Southeast, the Gulf Coast and the Ohio Valley woke up to sub-freezing temperatures.

Upstate New York had single-digit readings and wind chills well below zero. At 7 a.m., it was 8 degrees below zero in Watertown, N.Y., with the wind chill making it feel like 20 below. In Saranac Lake in the Adirondacks, it was 17 below with calm winds.

The coldest reading in Maine was 33 below near the St. Pamphile border crossing with Canada. Detroit was 6. Ohio saw 9 degrees at Cleveland Hopkins Airport, 8 in Youngstown and 7 in Dayton.

People shivered overnight inside about 1,000 homes that lost power in the Cincinnati suburb of Madeira after a vehicle hit a utility pole around 12:30 a.m. Duke Energy indicates nearly all the customers were back on by 6 a.m.

On the West Coast, a trio of rainstorms was expected to hit Southern California, with the first band of showers set to arrive Thursday afternoon or evening. The heaviest precipitation is expected Friday night into Saturday.

From Thursday to Monday, lowland areas around Los Angeles and Orange County were expected to get a total of up to 4 inches, while mountain areas of Southern California could get 10 inches.

Officials urged homeowners in mudslide-prone areas to stock up on sandbags, monitor the news for evacuations and keep an eye on streams and flood control channels for flooding. Fire stations throughout the region were handing out free sandbags.

The storm could dampen the San Diego Chargers' playoff game against the Tennessee Titans on Sunday. A Qualcomm Stadium official said that if the rain persists, the field will be covered by a tarp until one hour before the game.

Citrus crops were not the only ones at risk in Florida. Around the state, farmers were checking on other crops that Florida produces in the winter for much of the country, from broccoli and cabbage in north Florida to strawberries, tomatoes, corn and citrus toward the south.

The early looks indicated that damage to most crops would be isolated and "not as bad as it could have been," said Terry McElroy, spokesman for the state Department of Agriculture and Consumer Services.

McElroy said most of the crops growing in north Florida can withstand cold snaps and were probably not damaged in the freeze. But it may be days before some farmers know for sure how much they have lost.

In Louisiana, strawberry farmers covered their crops with material in an attempt to protect them. Peach farmers, however, welcomed the cold, which they say benefits their fruit trees during their period of dormancy.

"The more cold weather we have, the better," said Joe Mitchum, a peach grower outside Ruston, La.

The unusually low temperatures led New Orleans emergency officials to enact a "freeze plan" on New Year's Eve, allowing homeless shelters to temporarily exceed their fire safety capacity. Six shelters took on 700 extra cots between them, boosting the city's capacity of about 400 shelter beds. The plan is expected to last through Thursday.

Snow fell Wednesday from Ohio through eastern Kentucky and West Virginia into parts of Virginia and Maryland. West Virginia's rugged Randolph County got 13 inches, the Weather Service said.

At least 40 of West Virginia's 55 counties closed schools Wednesday because of snow-covered roads and freezing temperatures. The holiday break continued Thursday for students in at least 35 counties as the effects of the storm lingered.

Dozens of schools also were closed Wednesday in southeastern Michigan.