Drivers are being advised to take care as thick fog descends on Cornwall.
The Met Office has issued a weather warning and said the fog could cause travel disruption.
A spokesman for the Met Office said: “Fog is expected to become widespread and locally dense again through Thursday night and Friday morning.
“The public should be aware of the likelihood of difficult driving conditions and some travel disruption.”
Forecasters said visibility could be reduced to less than 50 metres.
The Met Office spokesman said: “Thursday morning's fog, having cleared inland, will have persisted through much of the day in some coastal locations and may begin to spread inland again quite early on Thursday evening.
“However, across most inland areas fog patches will form more widely overnight into Friday morning.”
The fog is expected to clear through the mid-morning.