More than 9,000 firefighters battle blaze which reduced 20,000 acres to ashes in just five hours.
Drought-ridden California was the scene of around 12 wildfires, with the biggest, the Rocky Fire, jumping over a highway that served as a containment line.
Donna McDonald, who is staying in a high school turned into shelter, said, "I'm overwhelmed, I was very happy at one point when I saw no smoke at all. Then all of a sudden it just flared up real big again."
The blaze turned more than 62,000 acres into ashes north of the state capital Sacramento, according to Sky News.
Fanned by its own flames, the inferno grew to three times its size over the weekend.
"The term that I'm using is 'historic'," one firefighter told CNN.
"The reason I say that is that there are firefighters who have 25, 30 years on the job who have never seen fire behaviour like we've seen the last couple of days."
In a statement to the San Francisco Chronicle, Battalion Chief Carl Schwettmann of the California Department of Forestry and Fire Protection said: "There were too many [spot fires] for us to pick up. With these drought-stricken fuels, it's just moving at an extremely high rate of speed."
Two dozen homes have been destroyed over the past few days and as of Monday (3 August) the fire was just 12% contained.
The California blazes killed a firefighter last week and injured four others, with a total of 142,000 acres burned so far.
California Governor Jerry Brown declared a state of emergency due to the wildfires.
Lightning strikes in the drought-stricken state were blamed for the fires.
In the immediate future, there is no rain forecast, which will make it even harder to get the fires under control.