The fire started at about 6:30am Thursday morning and reached 5,000 acres in three hours, fueled by high winds.
The Camp Fire has scorched over 28 square miles in Butte County, which is about 90 miles north of Sacramento, according to Cal Fire.
Adventist Health Feather River, a hospital in Paradise, evacuated its patients on Thursday afternoon.
Shari Bernacett said she and her husband tried to get people to leave the mobile home park they manage in Paradise and had minutes to evacuate.
With limited escape routes from the town, traffic accidents turned roads into gridlock, with residents abandoning vehicles and running from the flames carrying children and pets, officials said.
May said the low humidity and the dryness of trees and brush are among the reasons for the Camp Fire and also pose a potential danger in Berkeley. "God help us!" Bernacett said before breaking down crying.
California is experiencing one of its worst fire years ever, with 251,610 hectares burned through Sunday in areas covered by Cal Fire, almost twice the amount during the same period of 2017 and almost triple the five-year average.
The blaze began early on Thursday and quickly charred 3,237 hectares, forcing the evacuation of the 27,000 residents of Paradise, about 240 km northeast of San Francisco, and other communities, the California Department of Forestry and Fire Protection (Cal Fire) said in a statement.
Twitter tears into 'Thugs of Hindostan' with amusing memes
Big, bloated, bombastic, Thugs of Hindostan is a period saga that banks exclusively upon action and spectacle for impact. Aamir Khan and Amitabh Bachchan's much-anticipated film 'Thugs Of Hindostan' has finally hit the theatres.
Tamera Mowry & Adam Housley’s Niece Passes Away In California Shooting
The bar shooting was the latest mass killing in the United States and was sure to revive the debate on gun control. Marine Corps veteran, and an investigation to determine the motive is still ongoing.
Ryan Giggs Backs Wayne Rooney’s Return To England
I am still able to look to the future with the squad we've picked, but we've talked a lot about the history of the shirt. I know what it meant to Sir Bobby Charlton when he came to St George's and we named the pitch after him a few months ago.
A local fire official said there were multiple injuries among civilians and firefighters.
Among them was Kim Curtis, who was searching for her grandmother, who told family at 8 a.m. today that she would flee her Paradise home in her Buick with her cat.
Cal Fire tweeted that the fire was "very dangerous" and urged people to follow evacuation orders.
Thick gray smoke and ash filled the sky above Paradise and could be seen from miles away.
Others described watching flames consume their property as they evacuated.
Weather forecasts showed numerous red flag warnings and wind alerts in the area Thursday into Friday.
Hospital spokeswoman Jill Kinney said all patients were evacuated.