At least 76 people have died across northern California and authorities are trying to locate more than 1,200 people.
More than 5,500 fire personnel are battling the blaze which has already destroyed almost 10,000 homes and covered 223 square miles.
One of the worst hit towns, Paradise, was visited by the US President Donald Trump at the weekend.
“We’re going to have to work quickly … hopefully this is going to be the last of these because this was a really, really bad one,” the president said on Saturday.
He pledged improved forest management practices would diminish future risks.
Mr Trump told reporters that lessons could be learned from Finland where crews "spend a lot of time on raking and cleaning and doing things" to clear forest floors.
Finnish President Sauli Niinisto said in an interview published Sunday in the Ilta-Sanomat newspaper that he spoke briefly with Trump about forest management but couldn't recall raking coming up.
“I think everybody’s seen the light and I don’t think we’ll have this again to this extent,” Mr Trump said in Paradise, the town largely destroyed by a wildfire ignited on November 8 that he called “this monster”.
“It’s going to work out well but right now we want to take care of the people that are so badly hurt,” Mr Trump said from what remained of the Skyway Villa Mobile Home and RV Park.
He noted “there are areas you can’t even get to them yet” and the sheer number of people unaccounted for.
“I think people have to see this really to understand it,” Mr Trump said.
Several burned-out cars were nearby. Trees were burned, their leaves gone. Homes were totally gone, some foundations and twisted steel remained, as did a chimney.
The fire was reported to have moved through the area at 80mph.
The president later toured an operation centre, met response commanders and praised the work of firefighters, law enforcement and representatives of the Federal Emergency Management Agency.
“We’ve never seen anything like this in California,” Mr Trump said.
The president took a helicopter tour en route to Chico before he toured Paradise.
A full cover of haze and the smell of smoke greeted the president upon his arrival at Beale Air Force Base near Sacramento, where he was met by Governor Jerry Brown and Governor-elect Gavin Newsom, both Democrats.
Both men said they welcomed the president’s visit, adding “now is a time to pull together for the people of California".
The President also visited Southern California, where firefighters were making progress on a wildfire that tore through communities west of Los Angeles from Thousand Oaks to Malibu, killing three people.
Mr Trump has pledged the full support of the federal government.
While in southern California, Mr Trump also briefly met families and first responders touched by the shooting at the Borderline Bar & Grill in Thousand Oaks more than a week ago.
Trump called the shooting at a country music bar, which left 12 dead, "a horrible, horrible event".