Heavy snowfall has left some roads in the west of the country impassable tonight.
A status yellow weather warning for snow, sleet, hail and ice is in place for all counties in the Republic, along with Fermanagh, and parts of Tyrone, Armagh and Down.
The warning will remain in place until midday on Sunday.
Overnight there will be a widespread sharp frost with some icy patches as temperatures will drop to between 0 and -4C.
Tomorrow will start bitterly cold and icy while wintry showers will continue throughout the morning with further accumulations possible.
The Bantry/Drimoleague Road (R586) is closed just west of Drimoleague following a serious car collision.
Kerry County Council says the Conor Pass northeast of Dingle is impassable, as are sections of the N59 near Clifden in Co Galway.
Gardaí advise avoiding the Wicklow Gap and the Sally Gap due to the icy conditions.
Motorists are reminded that it can take up to 10 times longer to stop a vehicle on icy roads. Anyone driving in icy conditions should make sure to slow down and keep well back from whoever is in front.
Met Éireann forecaster Andrew Doran-Sherlock says the snow might not stick everywhere, but people everywhere will need to watch for ice.
"Even where there aren't very large accumulations or where it is more of a dusting, with the low temperatures there will be icy conditions on paths and roadways so people will need to take care."
Mr Doran-Sherlock said the wintry conditions look set to continue well into tomorrow in some parts.
"There will be falls of sleet, snow and hail for most areas with accumulations developing.
"By tomorrow morning it will be over to the east and will push in to the Irish Sea.
"But this is associated with a little low pressure system. It is going to stall in the Irish Sea and wrap around so there will be a little bit more then coming in along eastern coastal counties tomorrow late morning possibly into the late afternoon and evening."
#Sneachta and #snow both trended on Twitter as people around the country shared snaps of the snowfall, scenic landscapes and children out playing.
Happening now in Ballyhaunis, the tiny humans in thos house have all absconded and are out there yelling their lungs out. pic.twitter.com/fbUSkz1nuj— Oluwaseun Ola (@ddiezworld) January 23, 2021
The cold, wintry spell is predicted to come to an end on Tuesday when it will change to much milder and wetter conditions.