The fire, which started early Friday in School Canyon, was about 30 percent contained. Most of the activity was in rugged wilderness away from homes, but fire officials worried dry Santa Ana winds from the northeast could send the fire back toward Ventura.
"If they blow that way, then it could blow back into the city," said Gilbert Portillo with the California Department of Forestry.
Friday morning, a wall of flames as high as 30 feet (9 meter) snaked along hillsides, and by early afternoon a huge plume of whiskey-brown smoke carried ash over the Pacific Ocean. In just a few hours, the wind-driven fire tripled in size.
The cooler onshore breeze late Friday helped lower the wind and temperature. Little smoke was visible Saturday, a sharp contrast to Friday when flames pushed toward a neighborhood of some 200 ridgetop homes.
Officials hoped to have the blaze contained by Tuesday. The cause remains under investigation.
A red flag warning increased fire danger because of warm, dry and windy conditions remained in effect until 6 p.m. Sunday. The National Weather Service issued a wind advisory, and said overnight winds could exceed 50 mph (80 kph), reported AP. P.T.