Met Éireann has issued a Status Yellow fog warning for all counties tonight, Monday.
Pockets of dense fog are expected to develop across the country, which may lead to significantly reduced visibility and potentially hazardous driving conditions lasting into the morning.
The warning is valid from 8pm tonight until 11am Tuesday morning.
The advice from the RSA is that motorists should use dipped headlights when visibility is reduced. Use your fog lights if visibility drops below 100 metres. Turn fog lights off when visibility improves.