Main Roads has issued the warning along with advice for motorists this morning.
The fog is expected to be worst between Thomas Road and Mortimer Road in both directions.
Motorists are urged to turn on headlights and keep a safe breaking distance between other cars.
Extra travel time should also be taking into account due to reduced visibility.
Scorching Christmas temperatures for Perth, Rockingham, Mandurah
It is going to be a scorching Christmas this year with temperatures set to soar across the State.
Teen charged over Baldivis arson attack
A 17-year-old boy has been charged over an alleged arson attack in Baldivis that police believe is linked to the illicit tobacco trade.
Concerns for missing boy last seen in Warnbro
Rockingham Police are urgently asking for the public's help to find a missing 11-year-old boy.
Baldivis Sports Complex officially complete with unveiling of final stage
The City of Rockingham's largest ever community infrastructure project is now complete.
Teen dies at Logue Brook Dam
A 19-year-old man has died at Logue Brook Dam near Harvey.
Mandurah named WA’s Most Accessible Community
Mandurah has been named WA's Most Accessible Community.
Police attend separate crashes in Lakelands and Port Kennedy
Two people on a motorbike have been rushed to hospital after a crash in Lakelands.
Fresh new look for Roger May Machinery Museum
The Roger May Machinery Museum has a fresh new look, with the recent completion of a new front veranda adding both charm and functionality to this well-loved local attraction.
Tragic end to search of missing FIFO worker
The search for a missing FIFO worker has ended in tragedy after the 25-year-old's body was discovered 11 days after he vanished.