A national status yellow low temperature and ice warning has been issued for Thursday and Friday.
It will run from Thursday at 10pm until 10am on Friday.
Met Eireann is warning of "hazardous conditions" with temperatures falling to minus four degrees.
A national weather advisory for wintery conditions will run until Saturday nationally.
Meanwhile, the Taoiseach insists all measures to address the cost of living crisis in the winter months are kept under review.
It comes as the country faces into the first cold snap of the winter, with temperatures set to plummet from Wednesday.
There are concerns some people may be concerned about turning on their heating over concerns about cost:
"Health comes first, so we would say to people you, you know, in the context of such cold weather, to make sure they have the heating on and particularly our senior citizens.
"And I think there are mechanisms if a person is in an emergency situation or needs emergency assistance that can be provided.
"We have provided significant supports now since to budget in the one off payments that we announced.
"So we believe that should enable people to get through the winter.
"But like everything, we keep everything under."