A new December record for cold temperatures has been recorded at Dublin Airport overnight as theyt hit a low of -11.4C.
Meanwhile, public transport services are due to stop later this evening.
Further salt shipments for roads have arrived in Ireland over night and this morning.
The NRA said these are being distributed and that there are sufficient stocks to treat primary routes.
Meanwhile, motorists are being advised to drive with extreme caution , even on primary routes.
Iarnrod Eireann and Dublin Bus are stopping services at 9pm tonight while the Luas will stop running from 8pm.
Andrew McLindon of Bus Eireann says the majority of routes are running countrywide.