A Status Yellow fog warning is in place at present for the entire country.
The warning from Met Éireann, effective since 5.15 am this morning, will remain in place until 10am.
Motorists are being warned that some areas of dense fog are causing difficult driving conditions.
Dense fog can seriously reduces road user’s visibility and makes driving dangerous. Drivers are advised to switch on dipped headlights and fog lamps, reduce speed and allow an extra safe distance from the vehicle in front.
The RSA is also advising vulnerable road-users such as pedestrians, motorcyclists and cyclists to ensure they are clearly visible to other road-users by wearing high visibility clothing and using lights.