As many as 6,000 firefighters were battling Tuesday a wave of wildfires raging across California, which is gripped by a historic drought and near-record temperatures.

Thousands of residents have been evacuated and buildings ravaged in at least one of the fires in northern California, while southern California has been hit by power blackouts as people turn their air conditioning up to full blast.

There are currently 12 major fires across the vast western US state, including near the town of Weed, where flames damaged or destroyed over 100 buildings including the local church.

"Since last year there are much more fires because of the drought," CalFire spokeswoman Alyssa Smith told AFP, adding that there have been 200 more fires this year compared to the same time last year.

On Sunday, about 1,000 people were evacuated near Yosemite National Park in central California. The blaze that began near Bass Lake burned 330 acres (133 hectares) in a matter of hours.

California, baking in temperatures of over 100 degrees Fahrenheit (nearly 40 degrees Celsius), is in the third year of its worst drought for decades, devastating its largely agricultural Central Valley in particular.

In southern California, near-record temperatures for a sixth straight day led to a surge in electricity use, triggering outages which left some 7,000 people without power.

California often faces fierce fires in the summer and fall, but wildfire season began early this year, with the extreme drought of recent months generating dozens more blazes.