Temperatures are set to drop to between -5 and -6 degrees in parts of Connacht and Ulster on Tuesday night, according to Met Éireann.
Saturday saw the coldest night so far this winter with a low of -5.9 degrees in Co Roscommon.
The cold snap, aided by a mass of cold air sitting over the west and north of the country for the past few days, is set to worsen in the immediate future with temperatures dropping to between -5 and -6 degrees – and maybe more in localised conditions.
While such low temperatures happen “a couple of times a year” according to Met Éireann forecaster Gavin Gallagher, day time temperatures on Wednesday will not rise above zero in parts of the midlands and west “and that is fairly unusual”.
For those seeking, or seeking to avoid snow, Mr Gallagher said “a band of precipitation” would move in from the northwest on Wednesday morning, travelling as outbreaks of rain, sleet and snow. Most of the snow – falls of about two to three centimetres – would be in Connacht and Ulster, making for hazardous driving conditions.
Mr Gallagher said there was a possibility of “a dusting”of snow in Dublin just after daylight on Wednesday “but precipitation of this kind coming from the northwest tends to have worn itself out by the time it reaches Dublin”.
Dublin is also set to be warmer than the rest of the country as an easterly wind brings warmer air in off the sea. The temperature of the Irish Sea at the moment is about eight to nine degrees, making it warmer than land.
Met Éireann’s detailed forecast said it would be very cold on Tuesday with frost and ice clearing slowly, persisting in some parts for much of the day.
It is expected to be cloudier at times over Leinster and Munster with scattered wintry showers of rain, hail, sleet and snow. Highest temperatures of just 1 to 4 degrees are expected, possibly colder in the west.
Tuesday night was predicted to be “bitterly cold” with widespread severe frost and ice. It will be dry with clear spells in many areas, however scattered wintry showers of hail, sleet or snow on higher ground will continue to affect eastern and southeastern counties.
The regional forecast for Dublin is for Tuesday to remain cold with frost and ice clearing slowly. Scattered wintry showers of rain, hail, sleet and snow will occur, but there will be some bright or sunny spells too. Daytime highs will be around 4 or 5 degrees with moderate north to northeast breezes.
Met Éireann has issued a small craft warning for northeast winds reaching force 6 at times on Tuesday, on Irish Coasts from Howth Head to Hook Head to Valentia.