Donegal County Council has reported the arctic airflow is set to continue over the weekend and into the early days of next week.
Weather is expected to be persistently very cold night time.
Daytime temperatures are expected to bring sharp to severe frosts and icy stretches on roads and footpaths.
Dense fog forming in places with patches of freezing fog and some showers of hail and sleet are also expected.
Further updates to warnings are expected in the coming days and the public is advised to take care when travelling on the roads.
The alert is valid from today until Tuesday at 11pm.
