Met Éireann is forecasting that temperatures could reach lows of -5 degrees Celsius tonight amid a national weather warning.
Icy stretches, sleet and snow will remain throughout the day with a Status Yellow Snow/Ice warning for Ireland in place until 7pm.
It has also issued a Status Yellow Low Temperature warning, which will take effect from 7pm and run until 10am tomorrow morning.
Snow carpeted many parts of the country overnight, affecting roads in some areas.
Met Éireann is warning of icy and hazardous conditions throughout today.
— Met Éireann (@MetEireann) January 24, 2021
Most areas will be dry tonight with some isolated wintry showers, with a widespread sharp to severe frost expected to set in along with icy stretches.
There will also be some freezing fog too, especially across the northeast and east, while temperatures across the country will range from -2 to -5 degrees Celsius.
Frost, fog and icy stretches will begin clearing on Monday morning, while wintry showers will affect the north and northwest.
Meanwhile, a Status Yellow Snow and Ice is also in place in Northern Ireland until 3pm.
AA Roadwatch is advising motorists to be cautious amid the icy conditions.
They are urging particular care around Clifden in Galway, on higher ground in Kerry, west Cork and Wicklow, and in north-eastern parts of Dublin.