Severe weather conditions are expected over the first half of this week with plummeting night-time temperatures.
Temperatures last night were down to as low as minus 4 degrees as a cold snap arrived from the northeast.
The weather will bring the threat of ice and black ice for motorists but snow is unlikely.
Met Éireann forecaster John Eagleton said clear skies will account for low temperatures at night everywhere.
Temperatures will struggle to get above 5 degrees today and it will be followed by another freezing night with temperatures of minus 3 degrees.
Tomorrow will be cold and dry though it may be wilder and wetter along the Cork and Kerry coasts. The cold weather will continue until Wednesday with a change towards damp weather towards the end of the week.
The wind direction means snow is unlikely.
“We think at this stage it will be generally dry. There is no indication on our models that snow will happen,” said Mr Eagleton.
He said there was no indication either on the forecast models for a prolonged cold snap in the run-up to Christmas as there was in 2009 and 2010.
Ireland has so far being spared the bad weather that affected the UK last week and caused the closure of Stansted and Luton airports for a time.
However, the Road Safety Authority has warned motorists to take additional care this week. It said black ice on roads poses dangers and freezing fog will also be a problem.
