People in about 30 homes were ordered to evacuate as a wildfire roared through a canyon in Southern California's Cleveland National Forest, burning through 2 ½ square miles of dry brush.

Fire officials called Friday evening's evacuation precautionary and no residences were immediately threatened.

The fire had been burning uphill and away from the homes all day but the potential threat of a down-canyon wind after sunset prompted the evacuation.

"The wind was very mild, and with increased humidity and lower temperatures we're not seeing rapid growth," Orange County fire Capt. Mike Petro said late Friday.

About 300 firefighters, aided by aircraft, battled the flames, which sent up a towering column of smoke that could be seen for miles.

Crews worked in steep terrain and temperatures that approached 100 degrees, with the high expected to hit 102.

The National Weather Service says high pressure combined with a weak offshore flow will create high temperatures throughout the weekend reaching up to 20 degrees above normal.

Cleveland National Forest sprawls over the rugged peaks of the Santa Ana Mountains straddling the Orange and Riverside county line southeast of Los Angeles.