A yellow low temperature and ice warning is in place across the country until Wednesday morning, with the same warning in place again overnight into Thursday.
The notices warn of very cold conditions with widespread frost and icy stretches.
Met Éireann said there may be hazardous conditions on roads and paths with some travel disruption. The first warning is in place until 10am on Wednesday, with the second one in place from 8pm until 10am on Thursday. Additionally, a snow and ice warning from the UK Met Office will be in place for Northern Ireland until Wednesday morning.
Tuesday night will be mostly dry with clear spells. A few showers will drift into northern areas, turning wintry at times. Lowest temperatures will be between 0 to minus 3 degrees, in a light to moderate northwest breeze.
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Wednesday will begin cold and crisp with frost and ice. It will be dry for most of the daylight hours with low sunshine, though a few wintry showers will continue to move into Ulster.
Later in the evening, a wintry spell of rain will move into west and southwest counties with local sleet. Met Éireann said it will be another cold day with highs of 3 to 6 degrees, in light to moderate mostly northwest winds.
Wednesday night will see some rain coming in off the Atlantic with falls of sleet and snow, mainly in the southwest. Patches of freezing fog and frost are likely to develop in other areas, with temperatures ranging between minus 4 and 1 degree.
Thursday will see the rain, sleet and snow showers clearing off in the morning with daytime temperatures of between 2 and 5 degrees, dropping to as low as minus 2 that night.
Friday, however, looks set to be cold, bright and mostly dry.
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