"I want to emphasis that it's not going to be a white Christmas," said Met Eireann's Vincent O'Shea.
"The one marked feature over the coming days is very mild weather. There will be no storms or anything like that," he told the Herald.
However, he also warned: "There will be a good drop of rain and Sunday is most at risk. We could have around 50mm of rain between now and Christmas."
And there is a chance of some hail on Christmas Day, so there could be some slippery roads.
The Road Safety Authority (RSA) has urged drivers to take extra care.
"Let's ensure that no more families in this country suffer and that this Christmas is a safe one for all," RSA chief Noel Brett said. "I would appeal to all drivers to drive safely this Christmas by slowing down, not driving while under the influence of drink, drugs or fatigue and to always wear a seatbelt."
He is also urging pedestrians and cyclists to ensure that they are visible when out and about in the dark weather this Christmas.