The advice on their website is to drive slowly using dipped headlights and fog lights when it’s really bad, not forgetting to switch them off when the conditions improve.

It says to drive at less than 20 mph if you can’t see further than 30 metres ahead – and avoid speeding up too quickly even if the fog seems to be clearing as you could find yourself in the middle of dense fog.

This morning’s mail plane was delayed because of the weather.

Jersey Met Forecaster Peter Munns says it’ll be a repeat of yesterday’s conditions with very thick fog during the morning but the chance of a sunny period in the afternoon, especially in the east of the Island.

The fog caused disruption at the Airport yesterday morning with all flights in and out of the Island delayed. Mr Munns says there’s likely to be more disruption to flights again this morning.

Senior Air Traffic Controller Les Smallwood said the Airport can’t upgrade its instrument landing systems to enable planes to land in thick fog because of the length of the runway which is determined by the cliff edge at one end and St Peter’s village and the petrol station at the other.