Met Éireann has issued a Status Yellow snow and ice warning for 13 counties in the south, midlands, southeast and northwest.
The warning was issued at 11:00am this morning (Tuesday, December 29) and will come into effect at midnight tonight.
The warning will be in place for 12 hours, expiring at 12:00pm (noon) tomorrow (Wednesday, December 30).
Met Éireann is warning that there is a risk of snow accumulations to lower levels over the course of the warning.
The UK Met Office has also issued a Yellow weather warning, for all of Northern Ireland except Co. Down and Co. Armagh.
Snow and ice may bring some disruption in these counties over the course of this warning, which is in place from 3:00pm today to 12:00pm tomorrow.
Weather for days ahead
The weather is set to remain cold, showery and blustery for the coming days, according to the national forecaster.
Today will be cold and blustery, with bright spells and scattered showers, some with hail and a risk of wintry falls over high ground.
Showers will mainly fall across the western half of the country this morning, spreading eastwards during the afternoon. There will be highest temperatures of 4° to 7° in fresh and gusty northwest breezes.
Tomorrow will have an icy start for many. Rain, sleet and snow across the southern half of the country will clear southeastwards during the day, with bright spells and scattered wintry showers following from the northwest.
It is expected to be a very cold day with maximum temperatures generally ranging 1° to 4°, but a little less cold in southern coastal areas.