A lull on Saturday allowed some containment of the blazes, in the north and south of the state, before hot dry Santa Ana desert winds return.
A search for bodies continues in the devastated northern town of Paradise, where 23 people are known to have died.
Two more people were killed in the southern fire, near Malibu.
An estimated 250,000 people have been forced to flee their homes to avoid three major blazes in the state.
So far this year an area larger than Belgium and Luxembourg has burned, well above the average.
California Governor Jerry Brown asked US President Donald Trump to declare a major disaster to boost the emergency response and help recovery efforts.
In a series of tweets in recent days, Mr Trump has drawn anger by saying that poor forestry management is to blame for the fires.
But he has now extended his sympathies to those affected.
The blaze known as the Camp Fire started spreading through Butte County on Thursday, and firefighters were powerless to stop it destroying the town of Paradise.
Another fire swept into the affluent southern beach resort of Malibu on Friday and had doubled in size by Saturday.
Known as the Woolsey, it had burned more than 83,000 acres (33,500 hectares) by late that day.
Among the towns under evacuation orders is Thousand Oaks, where a gunman killed 12 people in a rampage on Wednesday.