The weather will stay cold for the rest of the week, with frosty nights and occasional wintry showers, according to Met Eireann.
Today (Monday) will be a cold day with sunny spells and scattered showers, it said.
Some of the showers wintry on high ground in the west and north and there will be highest temperatures of just 3 to 7 degrees Celsius, Met Eireann has said.
It will become windy too, with strong and gusty northwesterly winds on Atlantic coasts extending to all areas later in the day.
Tonight will be cold and windy with strong and gusty northwest winds and there will be frequent blustery showers in the north and northwest, some heavy and wintry, according to Met Eireann.
Met Eireann has said that tomorrow (Tuesday) will be cold and windy again with sunny spells developing in most areas, but there will be showers too, heavy in the east and north.
It will become less windy and less showery later in the afternoon with highest temperatures of just 3 to 7 degrees, it said.
Strong and gusty northwest winds will decrease moderate to fresh by nightfall.
It will be cold on Tuesday night, with frost setting in soon after dark and giving some ice in places, Met Eireann has said.
Met Eireann has said that this could well fall as snow on the higher ground and there will be lows of 2 to minus 2 degrees.
Fresh and gusty northwest winds will decrease moderate southwesterly overnight also.
Looking to Wednesday, Met Eireann has said it will be cold and mostly cloudy, with rain or sleet in many areas for a time.
A clearance will follow from the west during the afternoon and evening with just a few showers, it said.
There will be top temperatures on Wednesday of only 3 to 6 degrees and moderate to fresh southwest winds will veer west to northwesterly later in the day and overnight and will be strong on Atlantic coasts, Met Eireann said.
Wednesday night will be a cold and frosty night with some wintry showers, especially in coastal counties of the north and west, with lowest temperatures of 1 to minus 2 degrees.
Met Eireann has said that the cold conditions will continue into Thursday and Friday.
There will be some sunny spells, but scattered showers too, some wintry, it said. Winds will be moderate occasionally fresh northwesterly and the nights will be frosty too, with icy patches.