Continuous downpour has caused severe flooding in many parts of the state.
"This storm was different from the standpoint that it was here much longer. It was more intense because of the prior storm, the ground was much more saturated, which led to a lot more flooding and a lot more rescues because of the ground saturation," said Barry Parker, division chief of the Ventura County Fire Department.
The communities are heavily flooded and roads bear resemblance to rivers.
Rainfall has caused soil on the mountainside to loosen. This has caused mudslides that endanger road traffic.
Experts say the growing frequency and intensity of such storms, interspersed with extreme heat and dry spells, are symptoms of climate change.