Powerful gusts also ripped the roof right off of a mobile home in Perris.
The National Weather Service issued a flash flood warning for San Bernardino County, but that was lifted by 5 p.m.
The thunderstorms didn't give much relief to firefighters. Lightning was blamed for sparking at least one brush fire in the Phelan area. Crews were able to keep the flames, which spread over five acres, from causing any structural damage.
Temps in Irvine soared into the 90s and other inland areas saw triple-digit heat.
The heat was enough to put ambulances on standby at The Grove, where teenage girls at an outdoor concert and fashion show started suffering heat distress.
Teen Vogue was throwing a big back-to-school event at the shopping center when some young girls fell ill. No one was sent to the hospital, but some did need medical treatment.
"Standing out here in the heat, getting excited over the concert," said Los Angeles Fire Batallion Chief Alicia Welch. "Probably not wearing the right clothes, not in the shade, not having things to eat."
Seventeen people complained of heat, but only five were actually treated. Most only needed water, cool air and a break from the sun.
Overnight lows were expected to be in the 60s and 70s with some humidity.
Sunday, temps were forecast to hit highs in the triple digits in the inland and valley areas, 90s and 80s in the mountains and metro areas, and 70s along the coast.
Officials announced extended hours at cooling centers in Los Angeles. The following places will be open from 10 a.m. to 9 p.m. through Saturday, Aug. 11:
- North Hollywood Senior Citizen Center, 11430 Chandler Boulevard, North Hollywood
- Sepulveda Recreation Center/Mid-Valley Senior Citizen Center, 8801Kester Avenue, Panorama City
- Sunland Park Senior Citizen Center, 8640 Fenwick Street, Sunland
- Sylmar Recreation Center, 13109 Borden Avenue, Sylmar
- East Valley Multi Purpose Center, 5040 Van Nuys Boulevard, Sherman Oaks
- Canoga Park Senior Citizen Center, 7326 Jordan Avenue, Canoga Park