Snow-ice Warning for Dublin, Kildare, Louth, Wicklow and Meath until midday on Thursday.
Heavy overnight snowfall has led to accumulations of snow between 5 and 10cm.
Snow showers will continue to occur during today and again tonight with further accumulations. Total snowfall up to midday Thursday may reach 25cm.
Dublin Bus is warning of significant disruption with most routes operating a limited schedule today.
Crews at Dublin Airport are working to clear the runways but a number of flights have been cancelled.
Passengers are being advised to check with their airlines for the latest updates.
Irish Rail says DARTs are running as normal.
Both red and green Luas lines are operating a significantly reduced service.
A spokesperson for the tram operator says they are assessing the lines at the moment and expect to have a clearer picture at 7.30am.