Sacramento, California: Thunderstorms sparked as many as 75 wildfires in a wilderness area in Northern California on Saturday as officials in the south got close to containing a blaze that destroyed several homes and forced thousands to evacuate.

Storms on Friday were responsible for the large number of fires in Shasta-Trinity National Forest, near Redding. Those fires range in size from less than a 0.4 hectare to more than 304 hectares.

None immediately threatened homes, said Forest Service spokesman Michael Odle. Teams moved in Saturday on the two largest fires.

South of San Francisco, a fire that burned homes and closed a stretch of highway was 90 per cent contained, said officials of the California Department of Forestry and Fire Protection.

Officials had expected full containment on Saturday, but hot weather and stubborn hot spots kept fire crews busy. So far, it had charred 255 hectares, or less than 2.59 sq. kilometre. Evacuation orders were lifted on Saturday, a day after roughly 2,000 people fled their homes.

About 650 firefighters were working in hot, dry weather to contain the blaze, which destroyed as many as 15 buildings, including several homes, and closed scenic Highway 1 in Santa Cruz County for hours, fire officials said.

The cause of the fire was still under investigation.

It was the third major blaze to hit Santa Cruz County in the past month. A 210-hectare blaze destroyed 11 buildings in the Santa Cruz Mountains, and a fire near Corralitos covered more than 1,700 hectares and destroyed about 100 buildings.

California has been experiencing a heat wave that has contributed, along with the state's driest spring on record, to tinder-dry conditions, ripe for wildfires.