Ireland recorded its coldest day since 2010 on Monday as temperatures dipped to -7.2C in Athenry, Co Galway.
On the island of Ireland, a weather station in Co Down recorded -9C early on Monday morning.
The chilly milestone was reached early on Monday while the maximum temperature reached anywhere in the country was a mere -3.1C in Ballyhaise, Co Cavan.
The cold snap will end at the weekend but temperatures could plummet even lower before then with Thursday night looking most likely to be the coldest of the week.
Met Éireann says temperatures could hit as low as -7C but Alan O'Reilly from Carlow Weather says some models shows temperatures in parts of the Midlands could hit as low as -10C.
The country is still in the grips of a number of Met Éireann weather warnings, including a Status Yellow low temperature and ice warning covering the entire country until Friday.
"Remaining very cold through the week with widespread sharp to severe frosts and icy stretches," Met Éireann said as it published the warning.
"Some showers of hail, sleet and snow will occur, mainly near coasts. Accumulations at lower levels are expected to remain low. Freezing fog will occur at times, with winds remaining light over land," forecasters added.
This weather is causing disruption to travel and to homes with frozen pipes and increased risks to vulnerable people.
The warning remains in place until 12 noon on Friday.
A Status Yellow warning for freezing fog was in place overnight for Connacht, Cavan, Donegal, Monaghan, Longford, Louth, Meath, Offaly and Westmeath. It remains in place until 10am on Tuesday morning.
It warned that "patches of freezing fog will persist overnight Monday and into Tuesday morning leading to hazardous driving conditions in some areas."
In its wider forecast, Met Éireann says it will stay "very cold throughout the working week with widespread frost and ice. Most areas will remain dry and bright with just occasional wintry showers near coasts. Winds will remain generally light."
"Very cold this morning with any patches of freezing fog in the north clearing. Frost and ice will persist through much of the day. Mostly cloudy in the southern half of the country today with rain in the southwest, falling as sleet or snow in places away from the coast, causing hazardous driving conditions. Otherwise, it will be dry, with brighter conditions in the north. Daytime temperatures between -1 to +4 degrees in light to moderate northeasterly winds, fresher in the southwest."
They also predict another "bitterly cold night but becoming generally dry and clear. There is the chance of an isolated wintry shower near coasts. Widespread frost and ice will develop with lowest temperatures of -7 to -1 degrees in a light to moderate northeast breeze."
They say it will again be cold and dry tomorrow [Wednesday] with crisp winter sunshine.
"There is the chance of isolated wintry showers near northern and eastern coasts. Highest temperatures of 1 to 4 degrees in light to moderate north to northeast winds," forecasters have said.
Wednesday night will be another very cold night with lowest temperatures of -6 to -1 degrees.
"Widespread frost and icy stretches developing. Remaining generally clear and dry in a light northerly breeze, though there will be isolated wintry showers in the north and northwest."
Thursday will be dry for most with plenty of sunshine.
"There will be a few showers of rain and sleet in the north and northwest. Daytime temperatures of 2 to 5 degrees in a light northwesterly breeze."
A few more wintry showers will occur in the northwest on Thursday night but otherwise it will remain dry.
"Patches of freezing fog may develop with lowest temperatures of -7 to -2 degrees in a light westerly or variable breeze. Widespread frost and icy conditions will persist.
"Friday will be a dry and bright day for much of the country but showers of rain and sleet will move into western areas through the day. Still very cold with afternoon temperatures no higher than 1 to 4 degrees in light to moderate southwest winds," forecasters predict.
It will be very cold on Friday night with some lingering showers of rain and sleet in western areas. Elsewhere will stay dry but there is the chance of an isolated shower in the south. Lowest temperatures of -5 to 0 degrees, according to Met Éireann.
Saturday will be a dry and bright day, apart from isolated coastal showers in the south and west. Turning cloudier after nightfall. Daytime temperatures of 2 to 6 degrees.
Beyond that, Met Éireann says: "There is a good deal of uncertainty in the forecast from Sunday onwards. Current indications suggest that it will turn more unsettled and milder with spells of rain at times."
More warnings could be on the way as a result of that unsettled picture with forecaster Cathal Nolan from Ireland's Weather Channel saying the cold spell could be replaced by hazardous stormy conditions.
He said: "The latest guidance from the forecast models indicate that the current cold spell looks set to end next Saturday as a milder southwesterly airflow takes charge and displaces the present colder airmass.
"Temperatures could well be 10-12 degrees warmer next weekend as opposed to the weekend just passed, however there will be coastal gales, with heavy rain and some weather warnings are likely to be issued. "
READ NEXT :
Get breaking news to your inbox by signing up to our newsletter