The California Highway Patrol was escorting traffic on Interstate 5 through the Grapevine area, Caltrans announced Wednesday, because of snow and dangerous driving conditions.
Parts of I-5 were closed because of snow Wednesday morning, and CHP escorts began around 4 a.m.
Northbound traffic was being diverted at Parker Road in Castaic.
By 7 a.m., the Grapevine had reopened in both directions, but conditions were still icy.
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Snowfall crews were working to remove snow on the roads and reopen them as weather conditions improve.
Another area affected by frosty weather was Highway 58 east of Bakersfield.
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Several jackknifed big rigs and drivers spinning out forced a closure of State Route 58 from Towerline Road east of Bakersfield to Exit 165 north of Mojave, Caltrans said.
By 7 a.m., the Tehachapi Pass had reopened in both directions.
After a relatively mild weekend, colder temperatures are expected to hit SoCal along with gusting winds in some areas Wednesday.
NBCLA Meteorologist Belen De Leon says breezy conditions make it feel even colder Wednesday.
"It's goin to be a winterlike day but at least we'll have the sunshine," De Leon said. "Put on the layers -- the beanies, the gloves."
Fast forward to the afternoon, and the sun is expected to come out.
Wind-prone spots like the Santa Ana mountains and Inland Empire may shake some trees.
A frost advisory is in effect for the San Fernando Valley and Santa Clarita Valley until 9 a.m. Wednesday. A freeze watch is in effect in the same areas until Thursday morning.
For the freeze watch, temperatures are expected to reach as low as 26 degrees.
In the Santa Clarita Valley, temperatures could fall as low as 29 degrees, with a freeze watch in effect through Thursday morning.
Burbank, Northridge, Universal City, Woodland Hills, Castaic, Newhall and Santa Clarita are under frost advisories and freeze warnings.
