Road conditions are treacherous in many parts of the west due to snow and ice.
Gardaí said the N59 near Clifden was one of the worst routes affected with many sections of the road impassable during the night.
They have advised that, while much of the snow has gone, the icy roads are now hazardous and motorists are urged to avoid the Clifden area due to treacherous conditions.
Many parts of Roscommon and Mayo were also hit by heavy snow showers with drifts in areas near Roscommon town, but all roads are passable with care.
AA Roadwatch has said the Conor Pass and the Ballaghisheen Pass in Co Kerry are impassable due to snowfall.
Particularly icy conditions have also been reported on the N21 between Castleisland and the turn-off for Knocknagashel and the N71 at Moll's Gap.
People are also advised to avoiding the Sally Gap, Wicklow Gap and all upland areas in Co Wicklow.
A status yellow snow and ice warning remains in place for every county in the Republic of Ireland until 7pm, with a low-temperature and ice warning coming into effect at 7pm until 10am tomorrow.
Met Éireann is warning that it will be very cold overnight, with temperatures forecast to drop as low as -5C in places.
A UK Met Office status yellow warning for snow and ice remains in place until 3pm for Armagh, Down, Fermanagh, and Tyrone.
A separate status yellow warning for ice comes into effect across Northern Ireland from 6pm and is in place until 11am tomorrow.
It is a snowy Sunday in many parts of the country, with gardaí urging the public to take care if making essential journeys.— RTÉ News (@rtenews) January 24, 2021
Footage shows snowy scenes in Co Galway this morning | Read more: https://t.co/bovb9uKvAs pic.twitter.com/WjtCy32RZZ