Met Éireann has issued a Status Yellow snow-ice warning for five counties, warning of icy stretches and accumulations of snow in some areas.
Issued at 10:00am this morning (Thursday, December 3), the alert will be valid from 10:00am today through to 7:00am tomorrow.
The snow-ice warning will affect counties: Donegal; Galway; Leitrim; Mayo; and Sligo.
Icy stretches and accumulations of snow in some areas are expected, Met Éireann warns.
Meanwhile, in Northern Ireland a yellow ice warning has been issued for counties: Antrim; Tyrone; and Derry.
Issued at 10:59am this morning, this alert will be in place from 5:00pm this evening through to 10:00am tomorrow. In affected counties, the UK Met Office warns that travel disruption is possible from icy patches.
For the Republic of Ireland in general today, Met Éireann says it will be a bitterly cold day with widespread heavy showers early on, some of which will be wintry, along with isolated thunderstorms.
Showers will gradually become confined to counties along the western seaboard, with spells of winter sunshine developing elsewhere.
It will be very cold tonight with a widespread sharp to severe frost and possible icy stretches.
Overall, it will be dry with long clear spells. However, a few wintry showers will persist closer to the Atlantic, along with isolated thunderstorms.
Lowest overnight temperatures of 0 to -3°, in light to moderate northwest breezes.