A nationwide Status Yellow snow and ice warning came into effect this morning.
It came into effect at 4am and lasts until midnight Tuesday for the entire country.
It is the second snow-ice warning to hit the country within 24 hours.
Met Éireann is this morning predicting a "cold, bright and breezy day", with sunny spells and scattered wintry showers.
The showers will be most frequent in the west and north, with drier and brighter conditions prevailing in the east and southeast.
Forecasters are warning of slippery roads and paths due to accumulation of ice on untreated surfaces.
Temperatures dropped to just -2C with north-westerly winds last night.
Road users are being advised to take due caution.