Thousands of people have had to flee their homes in areas near San Francisco after several wildfires quickly move through the area.
California Governor Gavin Newsom has declared a state of emergency as authorities tackle hundreds of fires burning across the state.
The city most at risk is the city of Vacaville, which has a population of approximately 100,000, located between San Francisco and Sacramento.
Officials went door to door overnight in a frantic effort to clean the homes.
According to firefighters, 50 structures burned down in Vacaville, and 50 others were damaged by the fire.
The blaze was reportedly started by lightning strikes and a heat wave on the west coast of the United States. Earlier this week, one of the highest temperatures on Earth ever was recorded in Death Valley in California.
As of Wednesday, across the western states of the United States, nearly 45 million people lived in areas subject to some form of excessive heat warning or heat warning.
The cluster of fires in the San Francisco Bay Area, called the LNU Lightning Complex, were blown by winds throughout Tuesday night and have now grown to 46,000 unconfined acres.
The blaze, which is larger than the city of Washington DC, has injured four people and threatens around 2,000 buildings in Vacaville, authorities said.
A video on social media shows flames burning through the gardens of residents of famous wine-growing counties Napa and Sonoma in California.
Smoke also blanketed the city of San Francisco, about 95 km south of Vacaville, on Wednesday morning.
Fires are also burning in the southern part of the state, where officials described “extreme fire conditions” amid the heatwave.
Meanwhile, the state’s energy provider pleaded with residents to use less electricity or face power outages that would leave millions of people without power for hours.
As of Tuesday evening, more than 37,000 customers across California lost power, officials told CNN.
So far this year, the United States has seen fewer wildfires than in 2019. According to the Reuters news agency, about 1.4 million fewer acres have burned this year, but the pace is expected to accelerate next month when the Santa Ana winds hit the south and El Diablo winds hit the north.