The fires started at around 4 p.m.
One fire that started burning in a field, jumped Singleton Road and started burning in another field. It spread from north to south.
Helicopters were brought in to drop water on the flames. Cal Fire has also called in to help.
Meantime, the larger fire was near Capitol Expressway. Officials called these fast-moving, wind-driven fires.
"It jumped Capitol Expressway, which is about six lanes of traffic, and it has proceeded south," SJFD Captain Reggie Williams said. "Right now we do have the head of the fire knocked down. We have requested help from Cal Fire, as you can see their helicopters up, doing some air drops for us."
"I heard explosions, little explosions, so I figured I needed to water this down," San Jose resident John Dan said. "If it gets close at least this'll slow it down."
No evacuations are in place, but residents who came out to look at the fires have been told to stay back.
Officials say eight to 10 acres burned and no injuries were reported.
