Evacuation orders have been given to 13,000 people in California as firefighters struggle to contain some 20 wildfires.
Some 9,000 firefighters worked throughout Monday in steep terrain and rugged conditions, officials said.
The biggest blaze – the so-called Rocky fire north of San Francisco – has already consumed more than 90 square miles (233 sq km) of land.
On Monday afternoon the fire jumped a highway that had been containing it.
At least 24 homes were destroyed as the blaze was whipped up by winds that fuelled the flames, our correspondent says.
“I’ve never seen a fire act like this one,” evacuee Vicki Estrella said.