Wind gusts along the 15 Fwy near Fontana knocked over one big rig and flipped a truck pulling an RV.
No injuries were reported and the upturned vehicles were not blocking traffic lanes.
Freeway alert signs are advising drivers of high-profile vehicles on freeways to pull over and wait out the winds.
In Malibu, firefighters are on high alert after last month's wind-driven Corral Fire destroyed 53 homes.
At Malibu Bluffs Park, sustained winds of 30 MPH were reported with gusts up to 40 MPH.
Those high winds have Malibu residents worried about the possibility of wildfires.
The National Weather Service issued a Red Flag Warning beginning at noon on Monday, and the winds have increased since then.
The winds are the strongest in the mountain canyon passes, like Latigo Canyon where last month's wildfires serve as a reminder of what the winds can do.
L.A. County firefighters have called in five strike teams, amounting to 100 extra firefighters and 25 extra fire trucks, positioned in and around Malibu, Agoura, and Calabasas.
"If we're able to get in front of it and get people in place, we have a good chance of stopping it. This last fire - the wind-driven fire ? was nearly impossible to stop," said LAFD spokesman Jon Maass.
In the valley, the winds were not as severe as other parts of the Southland. But firefighters were still prepared for the worst.
The winds made a mess of Porter Ranch, scattering trash cans and bending trees.
The Santa Clarita Valley is bracing for strong winds Monday night. Advisory signs along I-5 warned drivers of the high winds.
Some residents who endured last month's wildfires will now have to face another round of dry winds.
"I'm very nervous. We've had many fires and scares," Porter Ranch resident Cheryl Oster said.
With the weather being clear and dry, fire officials are on alert for wildfires.
Cal Fire has brought in extra engines and a strike team from central California. They're on standby in the Santa Clarita area.
"It's scary, but I'm glad they're on alert. They were so awesome last time, I know they won't let us down," said Tammy Gabriel, who was evacuated during the recent fires.
"When we start dealing with sustained, single-digit humidity, that becomes a concern for us. Complicate that with the wind, and we've got a formula that could put an incident together for us," L.A. County Fire Dept. Batt. Chief Bill Niccum said.
Extra strike teams are on the ground throughout L.A. County and have been prepared for the past several weeks.
Residents are keeping their eyes and ears open for any suspicious activity.
The Red Flag Warnings are expected to last through Tuesday.