The weekend heat wave continued Monday, closing out one of the hottest Augusts on record.
As temperatures stayed well above normal, reaching triple digits in some cities, residents dealt with electrical blackouts and authorities coped with brush fires.
About 100 firefighters battled a 30-acre blaze in the Cleveland National Forest that scorched the earth and sent acrid smoke across south Orange County through the afternoon and evening.
"It was horrendous," said Steve Hallgren, a firefighter with the state forestry service. "You should have seen the smoke and flames."
Two firefighters were treated for heat exhaustion.
"It was very warm out there," said Kymbra Fleming, a spokeswoman for the Orange County Fire Authority. "We have commanders monitoring their condition so that we don't overwork these firefighters. We have a canteen set up to keep them hydrated."
The agency sent the first crews to battle the canyon blaze about 12:30 p.m. Authorities said several crews of county firefighters and jail inmates were expected to work through the night digging a fire line to confine the blaze and keep it from spreading beyond the steep, rocky terrain near Holy Jim Canyon. Arson investigators also were at the scene to determine the cause of the fire.
No structures were damaged, and fire authorities said they hoped to extinguish the blaze by tonight.
Officials warned that weather trends suggested the risk of fires will continue to climb in the weeks ahead.
"We're really only seeing the beginning of the true fire season," said Steve Markkanen, a senior forecaster with the National Weather Service. "There's a lot more plant growth than usual because of El Nino rains, which lasted until well into the spring, and all that brush and grass are now at the point where they're getting extremely dry."
Temperatures lingered near 100 degrees for a fourth day. Orange County's highs were in Santa Ana and Irvine, both of which recorded 100 degrees, said meteorologist Jeff House of WeatherData Inc., which provides forecasts to The Times.
The highs were slightly lower in the coastal cities of Laguna Beach and Newport Beach, which recorded highs of 93 and 90, respectively.
The heat wave is being caused by a high-pressure system centered off the California coast, House said.
Temperatures should continue falling slightly each day through the week, he said.
