Met Éireann have issued an orange weather warning for the next two days.
A rainfall warning is in place for east Munster, Leinster and east Ulster.
A status orange alert is in place until 6am tomorrow in Leinster and counties Cavan and Monaghan.
Heavy rain - ranging from 25 to 40mm - has already fallen in places, with further rainfall of up to 60mm expected.
Meanwhile, a status yellow rainfall warning remains in place for Tipperary and Waterford.