Cerritos Elementary School, which had eight of its 22 classrooms destroyed by fire, will open in the fall as scheduled, a spokeswoman for the ABC Unified School District said.
The district will replace the destroyed classrooms with portable ones, said Terry McAlpine, public information officer.
The cost of the portable classrooms has not yet been determined, but school officials have decided to open the school on Sept. 15 as planned, McAlpine said.
A late-night fire July 12 caused about $300,000 in damage to the school, according to the Los Angeles County Fire Department.
Seven fire companies were sent to the school. The blaze was controlled in about 45 minutes.
One firefighter was taken to Pioneer Hospital in Artesia, where he was treated for heat exhaustion and smoke inhalation.
The cause of the fire is under investigation by county investigators.