Met Eireann said today there will be no let up in the freezing weather for at least five days, with temperatures set to plummet to minus 10 next week.
Ireland is set to have the coldest December on record.
Gardaí are reminding motorists to exercise extreme caution as roads around the country remain treacherous following heavy snowfalls and freezing conditions.
Irish Rail and Dublin bus are reporting full services.
Bus Éireann is running but there are some cancellations, including between Cork and Limerick cities.
Dublin, Cork and Shannon airports are open and fully operational but delays are expected.
Met Eireann's Ger Fleming said people should prepare for more harsh weather.
"We are still looking at another three or four very cold days, up to the middle of next week," the meteorologist said.
"Air temperatures (will be) progressively falling as we go through the next few days and nights.
"By the time we get to the middle of the next week we could see temperatures down to… minus 10 Celcius across the country."