Met Eireann have issued a fog warning for Ireland.
The orange weather alert is in place from 10pm tonight until 11am tomorrow morning.
They have said that it will result in visibility being reduced to less than 100 metres in many areas.
As a result the RSA is warning road users of the dangers of driving in heavy fog.
Motorists are being advised to switch on their dipped headlights, reduce their speed and keep a safe distance from the vehicle in front.