The rare May rainstorm moved into northern Los Angeles County around 3:30 a.m., with showers soaking Orange County, the Inland Empire and the mountains by mid morning.
One-fourth inches of rain were expected in L.A. and Orange counties. A high of 68 was expected as some sunshine enters later in the day.
Rain in the Valleys and Inland Empire will be between one-fourth to one-half inch with highs around 69 and partly sunny skies.
Rain-slick roads slowed down drivers across Southern California, including on the 91 Freeway in Corona where a big rig fire shut down the right two lanes - making a messy commute even worse.
On the 101 Freeway near Calabasas, Eyewitness News reporter Marc Cota-Robles warned of slippery road conditions.
"Good chance (California Highway Patrol) is gonna be very busy this morning. Slow down, use some common sense - roads are gonna be slick" he said.
Steady rain fell through the morning in Pasadena, creating a muddy mess that some in the area actually enjoyed.
Edie Tyebkhan took her dog Copper to Alice's Dog Park to enjoy some romping in the rain.
Some residents in Ontario said they didn't mind the rainy conditions either.
"This year, it's been more greener than ever so I like that a lot, and the flowers are looking better. It's really nice," resident Rosa Mijangos said.
Light drizzle was falling in the morning in Malibu, where business and homeowners were bracing for mudslides in the burn areas. Eyewitness News reporter John Gregory said new vegetation was expected to deter mudslides in the burn areas, which hadn't seen heavy rain in weeks.
"The National Weather Service is saying we could see some minor mudslides, some minor mudflows. Keep in mind, we had all that rain over the winter, we saw a lot of growth on those hillsides, those burned hillsides. That should help hold things in place," Gregory said. "But it's Malibu, we see rockslides up here all the time, so that sort of thing could still happen.
The system moved out of the region around 10 a.m.
Another round of rain could soak Southern California on Sunday.