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.
New logo, website, ticketing system for Mandurah Performing Arts Centre
The Mandurah Performing Arts Centre (ManPAC) has undergone a fresh rebrand.
Perth, Mandurah households and businesses urged to turn off sprinklers now
Households and businesses across southern WA are being urged to switch off their reticulation from today, one week ahead of the the annual Sprinkler Switch-off.
Wannabe barbers caught on CCTV in bizarre Rockingham break-in
Two men have allegedly been caught on CCTV in a bizarre barbershop break-in.
Mandurah residents encouraged to have their say on proposed 4.95% rate increase, Long Term Financial Plan
Mandurah residents are being encouraged to have their say on the City's Long Term Financial Plan and a proposed 4.95 per cent rate increase for the 2026-27 financial year.
Developers sought for more housing in Rockingham
The State Government is calling on experienced developers to deliver more housing in Rockingham.
Lamp electrical fault deemed the cause of Parmelia house fire
Fire has completely destroyed a Parmelia home.
Elderly man, woman injured in South Western Highway crash
Police are calling on witnesses to a serious crash in Whitby near Mundijong.
Mayor denies Waikiki Primary School told to revert back to traditional siren
Rockingham Mayor Lorna Buchan has denied claims that the City ordered Waikiki Primary School to revert back to a standard siren during the school day after a complaint from a nearby resident.
New AI safety cameras capture shocking images of unrestrained children
The State Government's new AI safety cameras have captured shocking images of unrestrained children.