Californian officials yesterday warned that “extreme” wind conditions were set to fan wildfires across the north of the US state as residents were ordered to evacuate and millions faced power cuts. Nearly 90,000 people were ordered to flee their homes in Sonoma County, north of San Francisco, a number that rose over the course of the day as the Kincade Fire spread after breaking out on Wednesday. California’s largest utility, Pacific Gas & Electric Co., said it expected to cut off power to 940,000 customers -- a precautionary shutdown that local media reported would affect about two million people. “The weather event could be the most powerful in California in decades,” PG&E said.