Temperatures are set to plunge further on Wednesday with possible accumulations of sleet and snow, according to Met Ãireann, after lows plummeted to -3 degrees overnight.
A nationwide yellow warning for low temperatures and ice remains in place until 10am on Wednesday with the same warning in place from 8pm until 10am on Thursday.
So far, there have been light dustings of snow in some areas amid widespread ice and frost.
Sleet and snow are expected on Wednesday, particularly in the south and southwest as a yellow snow and ice warning for Munster comes into effect at 8pm with accumulations expected.
A snow and ice warning from the UK Met Office also remains in place for Northern Ireland until Wednesday morning, with heavy showers in some areas overnight.
Nationally, Wednesday is set to be a cold day with frost and icy stretches on untreated surfaces this morning, and this frost and ice will linger in some spots through the day making travelling conditions difficult in some areas.
Although it will be dry and sunny for many, scattered showers of sleet and snow will continue in the north and northwest.
Conditions will turn cloudier in the afternoon with a spell of heavy rain moving into the west and southwest, turning to hail, sleet and snow at times as it spreads inland.
There will be afternoon highs of 3 to 6 degrees, the forecaster said.
âVery coldâ conditions are forecast for Wednesday night, reaching lows of between -4 and 0 degrees with more widespread frost and ice.
Sleet and snow accumulations are possible, Met Ãireann said, as rain spreads across the southern half of the country later on Wednesday, turning to sleet and snow at times away from coasts.
It will be mostly dry further north, with scattered wintry showers continuing in Ulster and north Connacht.
Outbreaks of rain, sleet and snow will then clear to the south on Thursday morning, leaving another âvery cold dayâ with showers of rain, sleet and snow most frequent across Connacht, Ulster and west Munster.
Some icy stretches will linger throughout Thursday with temperatures reaching just 1 to 4 degrees.
The wintry conditions are set to continue until the end of the working week when it will turn milder, reaching highs of 12 to 15 degrees on Saturday.
However, conditions will turn more unsettled with potentially wet and windy weather, the forecaster said.
