A wildfire was burning out of control Sunday across 125 acres of hillside brush and trees in Riverside County, prompting authorities to order voluntary evacuations for 100 homes, officials said.

The fire threatened about 300 homes in Lake Elsinore, according to Capt. Julie Hutchinson of the California Department of Forestry and Fire Protection.

It broke out Sunday evening and chewed through dense brush and trees covering hills west of Lake Elsinore and north of Highway 74, she said. Nearly 230 firefighters were working the blaze.

"We're definitely concerned about it growing," Hutchinson said.

Cool weather dipping into the low 40s and light winds were forecast for early Monday.

"The weather is cooperating with us," CDF spokeswoman Cheri Peterson said.

It was the lastest in a series of major Southern California wildfires in recent months. The fire was 40 miles from the site of last month's arson-sparked blaze that killed five firefighters and destroyed 34 homes.

The cause was under investigation.

Lake Elsinore is located about 75 miles east of Los Angeles.