More than 25 million Californians are under a fire warning for wildfires in both the northern and southern parts of the state.
Hot dry winds are making it difficult for firefighters to battle the blazes.
A fire that erupted in Sonoma Country, north of San Francisco, Wednesday has already destroyed the entire town of Geyserville. About 2,000 county residents were forced to evacuate their homes Thursday.
Pacific Gas and Electric began a series of power blackouts Wednesday, cutting electricity to power lines to prevent them from sparking any new blazes in case the winds blow them down.
Gusts up to 97 kilometers an hour (60 mph) could also knock dry tree branches into active power lines and spark wildfires.
Active power lines sparked the fires that devastated parts of northern California last year, leaving 85 people dead and reducing entire towns to ashes.
PG&E was forced to declare bankruptcy earlier this year as it faces billions of dollars in lawsuits from residents who lost everything.
The exact cause of the fires are unknown, but forecasters blame them in part on dry conditions made worse by hot winds that blow west from the desert.
They say they expect the windy conditions to ease in the north but remain intense in the south until sometime this weekend.