By Monday morning the acreage burned had jumped to 4,100.
The rain should help drench the flames.
Around 128,285 acres (51,915 hectares) have been blackened by California wildfires from January 1 to November 24.
Santa Barbara County declared an emergency late Monday, saying in a news release that the fire was beyond the capabilities of the county's firefighters to control alone.
Some 5,481 residents were forced to switch away their properties in step with Santa Barbara County Sheriff Bill Brown, but some residents on the western flank of the fire were being allowed to return dwelling by Tuesday afternoon.
Firefighters at night were working "under some of the toughest firefighting conditions anywhere in the world", Los Padres National Forest Fire Chief Jimmy Harris said, in part because high winds were pushing flames downhill and then back uphill.
No homes have burned and the blaze in the mountains above Goleta in Santa Barbara County was 10 percent contained Tuesday after burning more than 6 square miles of forestland and brushy foothills.
White House Lockdown Lifted After Plane Flies Overhead
Capitol and its office buildings were briefly evacuated Tuesday over a report of a possible aircraft in restricted airspace. The evacuations at the Capitol were issued as a precaution and lasted around half-an-hour.
In just a few hours, the Cave Fire had shot down the 154, jumping the highway near Windy Gap and causing spot fires to break out in such locations like San Antonio Creek Road, where structures had flames bumping right against them, said Capt. Bertucelli of the Santa Barbara Fire Department.
The office of Gov. Gavin Newsom also said it was monitoring the fire Monday.
As of Tuesday morning, 600 firefighters had been sent to quell the fire, and there were no reported injuries or destroyed homes, he said.
Mandatory evacuation orders are in place from Ontare Road to Fairview Ave. north of Cathedral Oaks.
A Red Cross Evacuation Center has been established at Goleta Valley Community Center, 5679 Hollister Road.
As of Tuesday morning, the strong winds have mostly subsided, forecasters said, though in some isolated mountain areas, gusts reached up to 80 miles per hour.
Small Animals: Goleta Animal Shelter, 5473 Overpass Rd.
The Los Angeles Times reported that 2,400 homes were under mandatory evacuation orders, and that the area's steep and rocky terrain made fighting the fire hard.