Wildfires have burned a record 2 million acres in California this year, and the danger for more destruction is so high the US Forest Service announced it was closing all eight national forests in the southern half of the state.

Two of the three largest fires in state history are burning in the San Francisco Bay Area. More than 14,000 firefighters are battling those fires and dozens of others more around California.

Wildfires have burned more than two million acres (800,000ha) in California this year, setting a new state record. Crews battled dozens of growing blazes in sweltering temperatures that strained the electrical grid and threatened power outages for millions.