LOS ANGELES -- Californians had hoped that the mammoth Arctic storm roaring through the West would bring an early Christmas present: badly needed rain to ease a four-year drought.

Instead, nature's gift has turned out to be a bitter blast of wintry weather that brought snow flurries to coastal cities and filled homeless shelters to overflowing as far south as San Diego.

Although temperatures here may seem high in comparison with the below-zero cold in much of the nation, Southern California is not prepared to cope with weather that a Washingtonian would consider normal.

Houses here often are poorly insulated, if at all, and the drought-resistant succulents and other plants common here do not tolerate prolonged cold.

Temperatures plummeted into the low 20s in inland agricultural valleys, threatening avocado, citrus, vegetable and strawberry crops. Farmers who face water reductions next year unless the drought eases turned on sprinklers and wind machines in an effort to save produce.

Water is run through rows of produce because it is warmer than the freezing air, and wind machines keep the warmer air circulating in the groves, raising temperatures at least 2 degrees, authorities said.

On Skid Row in Los Angeles, free blankets were gone by noon Thursday, and every shelter was filled. In downtown San Diego, a homeless man, trying to keep warm, suffered severe electrical burns after crawling into a transformer box.

Snow fell in the central California seaside city of Monterey, delighting residents to whom it was a rarity.

Snow also came down in the Painted Cave area near Santa Barbara, scene of a disastrous fire last summer. "Fire and ice," said Anna Hanley, looking at snow on cars and trees. Callers to radio news shows reported snow flurries in the Southern California cities of Pomona and San Bernardino. "I know what snow looks like because I'm from Pennsylvania," one caller said.

For most Californians, low temperatures were of greater concern. In San Francisco Thursday, the temperature was a record low 34 for the date, one degree below the mark set 82 years ago.

The thermometer reached the freezing point yesterday morning in Santa Barbara and the mid-20s farther inland. After three hours in 26-degree weather, citrus crops in the San Joaquin Valley were saved from destruction at least temporarily by a timely wave of clouds that helped to raise the temperature.

Particularly threatened is the $400 million crop of navel oranges, which is ripening two weeks late this year with rinds thinner than usual. That gives them less capacity to resist the cold.

But people suffer most. California has a huge population of homeless people, many of whom rarely see the inside of a shelter. Now, the shelters are full, and a group of homeless activists has launched a campaign to pressure Los Angeles County into keeping its shelters open for the next 60 days.

"It's a matter of life and death," said John Suggs, director of the Los Angeles Countywide Coalition for the Homeless.

The county now keeps shelters open only on days when the National Weather Service predicts rain or overnight temperatures below 40 degrees. County officials said changing the policy would further threaten health care programs already cut. The city of Los Angeles already keeps shelters open continuously.

Meanwhile, three indigents sued the county in a class action contending that monthly relief payments of $312 are insufficient for food and shelter. County supervisors ignored recommendations of the welfare director to increase payments.

It has long been a premise in Southern California that even the poor enjoy a better life here because of the amenities of climate. That premise is being severely tested in the cold nights along Skid Row. -- Lou Cannon and Jill Walker