Wildfires in northern California – sparked by almost 12,000 lightning strikes – have grown into some of the largest in the state’s history.
One of them is within a mile of the University of California Santa Cruz, with residents in the city being told to have evacuation “go bags” already packed.
Bulldozers have dug fire lines on the northern edge of the university’s campus.
Most of the fires are in the San Francisco Bay Area. The biggest, known as the SCU Complex, east of Palo Alto, is covering an area approaching the size of New York City.
Across the state, at least six people have died, 43 firefighters and civilians have been injured, and more than 500 homes and other structures have been destroyed.
About 175,000 people have had to leave their homes.
Around 560 fires have been fought, and an area larger than the US state of Rhode Island has been burned.
The dry-lightning storms are California‘s worst in almost two decades, and have been driven by record temperatures, which have parched the land.
Last weekend, the temperature at Death Valley in the Mojave Desert reached 54.4C (130F) – one of the hottest air temperatures recorded anywhere on the planet for at least a century.
Almost 12,000 firefighters are on duty, and crews from Oregon, Idaho and Arizona have arrived to assist.
Governor Gavin Newsom said the fierce heat was caused by climate change and that more lightning storms were expected on Sunday.
“If you are in denial about climate change, come to California,” he told the Democratic National Convention.