Freezing fog is set to hit parts of the county this morning.

Motorists and commuters are being warned to take extra care and journey times may be longer as Valentine's Day gets of to a foggy start.

The Met Office has issued a yellow weather warning across Dorset as fog is 'very likely' and visibility will be less than 100 metres in places.

The warning is in place until 11am as the Met Office says it will be slow to clear this morning.

People are advised not to travel if possible and drivers are warned to watch their speed as fog can give the illusion of moving in slow motion.

Due to low temperatures, foggy patches could freeze in places causing travel disruption.

Freezing fog is made of water droplets which freeze on contact with objects such as the pavement, roads and cars and can quickly form a layer of ice.

The conditions may cause delays to bus and train services meaning journey times will be slower.

There is also a chance of delays or cancellations to flights.

A spokesman for the Met Office said: "Travelling in fog can be extremely dangerous. Fog can drift rapidly and is often patchy. Warnings of dense fog are issued when visibility is expected to fall below 200 metres. Severe disruption to transport occurs when the visibility falls below 50 metres."

According to the Highway Code, driver must use their headlights when visibility is seriously reduced - generally when you cannot see for more than 100 metres.

The RAC offers the following advice for driving in mist and fog:

  • When there is fog around, make sure you are familiar with how to operate your front and rear fog lights
  • If your car has automatic lights, remember to check the lights are on, as they may not be automatically activated in foggy conditions. However, do not use full beam lights, because the fog reflects the light back, reducing visibility even further
  • Follow the ‘two-second rule’ to leave sufficient space between you and the car in front
  • If visibility is very limited, wind down your windows at junctions and crossroads to allow you to listen out for approaching traffic. If you really cannot see, you should consider stopping until it is safe to continue
  • If your car is fitted with air conditioning, use it, as it will stop the windows from misting up. Ensure the heater is set to windscreen de-misting and open all the vents
  • If the fog is so severe that you’re struggling to see other vehicles, switch on your fog lights
  • Read more about driving in mist and fog

After 11am it is due to be a bright but chilly day with sunshine forecast throughout the day and temperatures reaching highs of nine degrees.