At one point on Saturday, containment was at 15%, but after the fire grew from 425 acres to 521 acres, Cal Fire dropped the containment to 10%. Later Saturday night, containment grew to 20%.
All of the evacuation warnings from Friday have been lifted, and evacuation orders have been downgraded to warnings.
The Pyrite Fire erupted around 5:20 p.m. Friday near Pyrite Street and Granite Hill Drive, according to Cal Fire.
Fire officials initially said the fire was burning in "light flashy fuels" and estimated it at 15 acres.
Evacuation orders issued for Jurupa Valley fire
Evacuation orders were issued and later expanded as the blaze continued to grow.
Evacuation areas can be viewed in the map below.
Crews used helicopters to make water drops, and Phos-Chek was also dropped on flames.
According to Cal Fire, a lane closure was in effect for the number two southbound lane on Sierra Avenue to allow access for fire resources and equipment.
In the latest update, Cal Fire said firefighters will remain on scene overnight to strengthen containment lines and patrol the perimeter. Evacuation warnings remain in effect.
Cal Fire noted that no injuries had been reported.
It's unknown what caused the fire.