RIVERSIDE, Calif. - Inland areas of Southern California faced another day of blistering heat as firefighters worked to contain several lightning-sparked brush fires in Riverside County.

Excessive heat warnings were extended through Saturday evening for areas of Los Angeles, Ventura, Santa Barbara and San Luis Obipso counties.

It felt more like a day in the Midwest than Southern California Thursday as hail, heavy rain and lightning pummeled parts of the region that earlier baked in triple-digit temperatures.

Thunderstorms rumbled in the hills east of San Diego, fanning fires in the Inland Empire and dropping hail in the high-desert Antelope Valley in Los Angeles County. It prompted flash flood warnings for most mountains and Antelope Valley.

More than a dozen fires were reported after the first band of thunderstorms passed through Lake Elsinore, Hemet and Diamond Valley, Riverside County fire spokeswoman Cheri Patterson said.

Two sheriff's deputies were injured while rescuing an elderly woman from a burning trailer in Lake Elsinore. One was treated for smoke inhalation, and the other suffered burns on his arm.

Some spot fires were quickly put out, but one near Temecula spread to more than 700 acres and was 15 percent contained, Patterson said. Two other fires near Hemet continued to burn late Thursday. One charred 350 acres and was 10 percent contained, another burned 70 acres and was 80 percent contained, Patterson said.

An unknown number of residents were evacuated at the height of the fires, but all were cleared to return by late Thursday, Patterson said.

A small fire dashed up a steep hillside in the Mission Valley neighborhood of San Diego before firefighters contained it, said San Diego Fire-Rescue spokesman Maurice Luque. Three more fires were started by lightning in the hills east of San Diego.

This week's hot, sticky weather followed weeks of a prolonged pattern of heavy morning and evening overcast with unseasonally cool temperatures, known as June Gloom.

"The culprit, if you will, is a large upper-level ridge of high pressure that's over the desert southwest, and it's pushed into Southern California," National Weather Service forecaster David Sweet said. "It's basically a big dome of warm air."

The Los Angeles Department of Water and Power urged residents to conserve eletricity by setting their air conditioners to 78 degrees and using energy-intensive appliances, such as washing machines and dishwashers, at night instead of during peak daytime hours.

The temperature should drop slightly Saturday, with a cooling trend beginning Sunday near the coast that will see temperatures drop seven to 12 degrees early next week, Sweet said.

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