The Grant Fire was first reported around 5.30 p.m. in Alameda County.
"[The Klamathon Fire has] destroyed structures, threatened homes and critical infrastructure and caused the evacuation of residents," said California Governor Edmund G. Brown.
In the days after the fire, residents rummaged through the debris, searching for salvageable belongings amid the destruction.
“Weather conditions remain critical,” the Rocky Mountain Incident Management Team said.
Some 200 firefighters were deployed to combat the flames.
The Friday-morning fire had already spread across some 100 acres.
The fire's behavior will be “somewhat moderated” by humidity in the Southern California region.
Thursday is anticipated to be the worst day of the wildfire.
Forecasters warn that the worst flames will come soon.
Winds of up to 60 mph are pushing the fire in the direction of the cities of Santa Paula and Ventura.
Cedar shake and shingle roofs are like having a pile of firewood on top of your house.