Met Éireann has issued a yellow fog warning.
The forecaster is advising that fog or freezing fog will develop this evening, becoming dense in parts of Munster and Leinster overnight leading to impaired visibility and hazardous driving conditions.
It said that fog will be slow to lift tomorrow and may linger locally.
The warning, which comes into effect at 8pm this evening, will remain in place until 12 noon tomorrow.
While generally dry conditions are expected over the coming days, frost and fog are expected to remain a feature.
The forecaster said frost and fog is expected to form by night, with fog persistent in places during the day.
Looking to next week, it said: "There is some uncertainty further out but current indications suggest that high pressure will continue to dominate our weather into next week with occasional weak fronts encroaching from the Atlantic at times later."