Winds pushed the fire west overnight, increasing its total area to 236,000 acres. Containment was estimated at 25 percent. It remains as the fifth largest wildfire in California history.
Fire officials said the blaze made its way further into Santa Barbara County, threatening the communities of Carpenteria, Summerland, Montecito and surrounding areas.
Thick smoke blanketed the area around Carpenteria as ash and soot rained down from the skies. It was difficult to see even two blocks down the street due to the thick haze.
Many residents were forced to wear masks and some businesses remained closed amid the toxic air conditions.
"This is pretty bad today. I think it's worse than it was yesterday," said banker Leo Fortunato. He said if his bank decided to open today, he'd consider wearing a mask even inside.
Firefighters were also prepared in case the fire moved closer toward the city of Fillmore.
Despite the active flames, Cal Fire officials described their efforts as successful along the Highway 126 corridor. They're not taking any chances, though, and have crews positioned above Fillmore just in case.
"We continue to have a challenge above Fillmore" said Mark Brown with Cal Fire. "We have personnel still in place should it flare up and move down the hill toward the town of Fillmore."
Currently, there are no mandatory evacuation orders in place within Fillmore city limits.
Santa Ana Winds are expected to persist in the fire zone as the red flag warning is expected to be in effect until Wednesday evening.
Also, single-digit relative humidity levels and high temperatures further fueled the flames.
MORE: List of evacuations, school and road closures caused by Thomas Fire
Since the evening of Dec. 4, when the inferno erupted in Santa Paula, it has destroyed 868 structures, most of which were single-family homes. Officials said Monday that 525 homes were destroyed in the city of Ventura, while 138 were damaged.
In unincorporated areas of Ventura County, 342 structures were destroyed and 49 were damaged. One home was destroyed in an unincorporated part of Santa Barbara County.
The damage caused also means the Thomas Fire is among the top 10 most destructive wildfires in the state's history, according to Cal Fire.
Mandatory evacuation orders remained in place for parts of Ojai, Casitas Springs, Matilija Canyon, Carpinteria and Montecito.
By Monday afternoon, all mandatory and voluntary evacuation orders were lifted for Ventura, with the exception of areas north of Foothill Road from Day Road to Kimball Road.
PHOTOS: Thomas Fire devastates Ventura County
Firefighters from 856 engine companies were involved in the firefight, whose cost has reached $38.37 million, according to Cal Fire. Twenty-seven water-dropping helicopters and 48 water tenders were also in the burn area Tuesday.
Firefighters believe they have a few more days of good weather to get a handle on the fire before the Santa Ana winds kick up again.
The cause of the blaze is under investigation. Southern California Edison said state officials are investigating whether the utility's equipment played a role in sparking any of the wildfires that have burned in Southern California in recent days.