Dense fog will creep inland overnight and ground frost and icy patches will make roads hazardous.
Gardai are advising road users to exercise caution as the dense fog is expected to develop overnight and visibility will be greatly affected nationwide.
Lowest temperatures tonight will be -1 to +3 degrees.
Met Eireann forecaster John Eagleton has warned that the weather conditions which are necessary for fog to develop are currently showing across the country.
“Tonight it’s very, very damp all over the country with very little wind. It’s cold and there’s a bit of cloud over the country so conditions are right for it.”
“Fog could happen countrywide. With fog that’s the nature of the beast.”
He said it’s vital that driver’s take care on the roads as visibility will be affected.
Met Eireann is also predicting scattered showers which will be heaviest in some coastal counties. These showers will become isolated and confined to western coasts early tonight.
Winds are expected to slacken but dense fog and ice will form overnight.