The mandatory evacuations were put in place in Montecito, neighbouring Summerland and a portion of Santa Barbara.
Workers at the Santa Barbara zoo began putting some animals into crates and kennels in the hopes that they can be evacuated.
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The 404-square-mile Thomas Fire was moving rapidly westward north of Montecito, home to Oprah Winfrey, Ellen DeGeneres and many other celebrities.
Winfrey tweeted: "Still praying for our little town. Winds picked up this morning creating a perfect storm of bad for firefighters."
The fire is now the third-largest in California's history, burning more than 700 homes and killing a firefighter.
Around 95,000 people have been placed under mandatory evacuation since the fire took hold on 4 December.
Pierre Henry, a Montecito bakery owner, said he received a text to evacuate on Saturday morning as the fire approached homes.
"The worst was the smoke," he said.
"You couldn't breathe at all and it became worse when the wind started. All the ashes and the dust on the street were in the air. It was very, very frightening."
Authorities say the fire has burned another six square miles of vegetation.
California Governor Jerry Brown said the wildfires ravaging his state should serve as a warning to parts of the world threatened by climate change.
"The important fact is that these fires are going to become a very frequent occurrence. That's what the science is telling us," Mr Brown said.
"It's a real indicator of bad things to come, and hopefully will serve to wake up people who right now are too complacent."
Santa Barbara County Fire Department Division Chief Martin Johnson said: "It's a beast... but we will kill it."