Firefighters on Monday continued to battle a brush fire burning in the hills above Gilroy, and officials said the changing weather could be a cause for concern.
The blaze was first reported just before 8 p.m. Sunday at 1980 Ballybunion Court and spread to at least 100 acres Monday afternoon, according to officials. There was 10 percent containment as of 4 p.m.
Cal Fire reported earlier that the fire had burned at least 130 acres.
The fire was climbing the hills near the Gilroy Gardens amusement park away from homes, and no homes or other structures were threatened, officials said Monday afternoon. But that could change depending on the weather.
Pam Temmermand, with Cal Fire, said the biggest challenge is the terrain.
"We're working in basically oak-woodland area," Temmermand said. "Pretty steep, difficult to get into."
Fire officials said heat and possible lighting strikes are also big threats. They caught a break with the marine layer and a few raindrops Monday morning, but it didn't last long.
"We're expecting to get some winds later today, and that's going to allow the temperatures to go up," Temmermand said.
Hundreds of families in the Eagle Ridge housing development were preparing for possible evacuation orders that could come at a moment's notice.
"It's pretty scary because we were out over there on the hill," resident Ryan Rahman said. "You can see how close the flame is."
Kaylee Rahman added: "We have somewhat of a plan. We packed our valuable items."
One firefighter was transported to a hospital after falling roughly 40 feet, officials said.
Based on the timing of the blaze, fire crews were unable to attack the flames from the air on Sunday. Firefighters thus had to battle the blaze on the ground before water drops could begin Monday.
"It's very, very difficult terrain," Mary Gutierrez, with the Gilroy Fire Department, said. "It's very steep."
Santa Teresa Boulevard remained closed between Miller Avenue and south of Club Drive on Monday. Fire officials asked the public to avoid the area to allow emergency vehicles access.
Smoke from the fire caused poor air quality in Gilroy and surrounding communities, and fire officials recommended residents remain indoors with doors and windows closed for safety.
Witnesses said the fire likely was caused by kids lighting off fireworks, but fire officials did not confirm the cause of the blaze.
The Gilroy Fire Department was being assisted by Cal Fire, San Jose, Mountain View and Santa Clara County fire crews.
NBC Bay Area's Laura Malpert contributed to this report.