The advisory is in effect for Los Angeles, Santa Barbara and Ventura counties until 8 p.m. Sunday. ABC7 meteorologist Jonathan Novack says the heat advisory in the Inland Empire expires Monday night.
The San Fernando Valley was one of the hardest hit areas, with triple-digit temperatures in spots Saturday.
MORE: Full Southern California forecast
Families in Lake Balboa were doing everything possible to beat the sweltering heat.
"The weather is really hot, but we are keeping cool by lots of water, emergency packets...definitely putting a hat on, sunglasses, lots of sunscreen," Los Angeles resident Bridgett Acuna said.
Those looking for a pleasantly warm weekend were met with temperatures in the upper 80s in Los Angeles and Orange counties, and upper 90s to low 100s for the valleys, Inland Empire and deserts.
"I was hoping to come to a cooler area, we're trying to get away from the heat, but it seems as though it followed us," Las Vegas resident Selina Palmer said. "It's horrible, I can't even believe it right now. I'm sweating, I feel like I'm back in Vegas."
A slight cool down is expected later next week.