The death toll in California’s wildfires passed 40 at the weekend, with hundreds of people still missing in the most lethal outbreak of bush fires in the state’s history.

More than 100,000 people have been forced to flee their homes as entire neighbourhoods are reduced to blackened ruins.

Authorities hope weakening winds will help more than 10,000 firefighters contain fires that have already consumed more than 330 square miles, an area larger than New York City.

“This is truly one of the greatest tragedies that California has ever faced,” said Jerry Brown, California governor, during a visit to the affected region.

“The devastation is just unbelievable. It is a horror that no one could have imagined.”