SAN DIEGO (AP) — The bright sun and clear skies were routine, but the cold was not, as Californians bundled up with sweaters and gloves and stocked up on firewood Friday to brace for several nights of freezing temperatures.

Zookeepers turned up the heat for chimpanzees in San Diego, and tourists covered their hands on Hollywood walking tours. Still, the cold snap wasn't enough to throw many off their strides.

"We love our 75-degree weather," said Tami Walker, 50, of Ventura. "Any time it gets cooler than that, everyone says, 'Oh, it's getting cooler.' If it starts to drizzle, people call each other and say, 'Run to the window.'"

Walker, part-owner of Urban Adventure Quest, which does self-guided walking tours in California's tourist meccas, said customers wore gloves and told her they expected a warmer vacation.

The National Weather Service is forecasting morning frost on San Diego beaches for several days. Big Sur, on the central coast, prepared for daytime highs almost 20 degrees below Boston's. Even the snowbird haven of Palm Springs faced the possibility of freezing temperatures at night.

In Sonoma County, homeless shelters started handing out extra warm clothes to protect people from freezing overnight temperatures.

Some customers drove more than an hour to buy firewood.

"It's crazy busy here, at least 50 percent more," said Renea Teasdale, office manager at The Woodshed in Orange, south of Los Angeles.

Still, it was business as usual as much of the state contended with temperatures in the high 40s and low 50s.

"It's still sunny Southern California, and I'm going to work on my legs all year long," said Linda Zweig, a spokeswoman for the Del Mar Fairgrounds, which is hosting a 5-kilometer run north of San Diego on Sunday. The lifelong San Diego-area resident is prone to wearing two sweatshirts when the temperature drops but refuses to give up on shorts.

Rae Walaska, a San Diego writer, was happy to return home Thursday night after spending the holidays with family in Boone, Iowa.

"I didn't even have my coat on at the airport, it was so nice," said Walaska, 32. "I'm walking out to the car and my husband is all bundled up in a jacket. I'm like, 'Are you for real?'"

In the San Joaquin Valley, the heart of California's citrus production, growers saw little crop damage.

They ran wind machines and water to protect their fruit, which can raise the temperature in a grove by up to 4 degrees, said Paul Story, director of grower service at California Citrus Mutual. Existing moisture, sporadic rain and cloud cover also helped keep in heat.

A 40-mile stretch of a major highway north of Los Angeles reopened some 17 hours after snow shut the route and forced hundreds of truckers to spend the cold night in their rigs.

The California Highway Patrol shut the Grapevine segment of Interstate 5 on Thursday afternoon, severing a key link between the Central Valley and Los Angeles.

"There must have been 1,000 Mack trucks lined up," said traveler Heidi Blood, 40