Met Éireann has issued an orange low temperature/ice warning for 22 counties.
The national forecaster has said it will be extremely cold from 8pm on Tuesday, with widespread severe frost, ice and lying snow.
Lowest temperatures will be of -3°C to -8°C generally, locally lower, with a severe frost and icy stretches.
Met Éireann added that light variable breezes will allow patches of freezing fog to develop.
These conditions are expected to last until 10am on Wednesday in Carlow, Cavan, Clare, Cork, Galway, Kerry, Kildare, Kilkenny, Leitrim, Laois, Limerick, Longford, Mayo, Meath, Monaghan, Offaly, Roscommon, Sligo, Tipperary, Waterford, Westmeath and Wicklow.
From Tuesday evening at 6pm until Wednesday morning at 11am, Leinster, Cavan, Monaghan, Munster and Connacht will remain in an orange low temperature warning.
Meanwhile, a status yellow low temperature warning for remains in place for the rest of Ireland until 6am Friday.
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