The 44-square-mile blaze at the western end of the Santa Monica Mountains is 60 percent surrounded Sunday.
Ventura County fire officials say full containment is expected Monday.
On Saturday authorities lifted evacuation orders for residences in several areas.
The National Weather Service says an approaching low pressure system would bring a 20 percent chance of showers Sunday afternoon, with the likelihood increasing into the night and on Monday.
The fire that broke out Thursday has caused damage to 15 homes.
East of Los Angeles in Riverside County, a new fire that broke out Saturday afternoon burned 650 acres of wilderness south of Banning. It is 30 percent contained.