LOS ANGELES - California hot spots have been shivering through frigid morning temperatures this weekend, leaving even polar bears at the San Diego Zoo seeking warmth.

In the Los Angeles area, the often sweltering San Fernando and San Gabriel valleys were below freezing before dawn today.

In San Diego, zookeepers offered extra heat and shelter for animals. While polar bears tolerate frigid climes, the zoo animals lack the fat layers that naturally occur in the wild to protect them from the cold.

But citrus growers in the Central Valley are expressing relief that most orange and lemon crops probably avoided significant damage. The growers' trade association California Citrus Mutual says temperatures were only a couple degrees lower than expected.

Spokesman Paul Story says "For the navel oranges, that's not cold enough to do a measurable amount of damage." But he adds that the smaller, more fragile mandarin oranges may have suffered.

It was the third night of successful crop protection for farmers, who run wind machines and water to protect their fruit. Story says growers will be prepared for more plunging temperatures tonight.