The record-breaking blaze was sparked just days after the year's previous largest fire raged in central California.
The Oak Fire near Yosemite National Park broke out in mid-July and spread rapidly, destroying 41 buildings and forcing thousands to evacuate.
California, which is facing a punishing drought, still has months of fire season ahead of it.
In recent years, California and other parts of the western United States have been ravaged by huge and fast-moving wildfires, driven by a warming climate.