Cal Fire on Saturday reported the LNU Complex of fires grew to 373,324 acres overnight and was 41 percent contained.
The blazes, burning in Sonoma, Napa, Lake, Yolo, Solano and Colusa counties, have killed five people and destroyed 1,080 structures.
Another 30,500 structures are threatened by the fires, which started Aug. 17.
At the fire's height, about 42,000 Sonoma County residents had been ordered to evacuate or warned that they may have to soon.
As of Friday afternoon, 2,127 residents were still evacuated and 1,507 residents were in evacuation warning zones, county officials said.