California is facing its worst fire season as the largest wildfire ever recorded in the state has now burnt an area close to the size of Los Angeles.
Historically, the worst months of wildfire season are still to come.
The fires, known as the Mendocino Complex, are burning around 100 miles north of San Francisco. There are 23 active wildfires which are being tackled as the same incident.
Since starting on 27 July, they have devastated 283,800 acres (443.4 square miles).
The latest of the 23 fires has burnt through more than 4,000 acres of brush and grass in Cleveland National Forest, authorities said.
The Holy Fire, named after the Holy Jim Canyon, where one of the fires began, saw 10 helicopters and five air tankers supporting firefighters on the ground.
Temperatures in northern California have been climbing and could reach 43C (110F), and winds up to 15mph have made the fires spread.
About 14,000 firefighters – including backup from Florida and even New Zealand – are struggling to control the fires.
National forest land and rural areas have been destroyed, and urban areas and neighbourhoods are under threat.
“For whatever reason, fires are burning much more intensely, much more quickly than they were before,” said Mark A Hartwig, president of the California Fire Chiefs Association.
Scott McLean, a deputy chief with the California Department of Forestry and Fire Protection, described the flames as “extremely fast, extremely aggressive, extremely dangerous”.
He added: “Look how big [the fire] got, just in a matter of days.
“Look how fast this Mendocino Complex went up in ranking.
“That doesn’t happen. That just doesn’t happen.”
The flames have raged in mostly remote areas, and no deaths or serious injuries have been reported, however at least 75 homes have been lost, and thousands of people have been forced to flee.
Previously, the largest fire in California history was December’s Thomas Fire, which was around 440 square miles and devastated the counties of Santa Barbara and Ventura.
It also killed two people, including a firefighter, and destroyed more than 1,000 buildings before it was brought under control on 12 January.