Dublin Airport was closed for half an hour this morning after snow created potentially dangerous conditions for inbound and outbound aircraft.
A spokeswoman for the Dublin Airport Authority said the airport was closed between about 7.30 a.m. and 8 a.m. while the main runway was cleared. She said there had been no inbound flights due at the time so it had not created major delays.
"Safety is obviously the main priority," the spokeswoman said. "The snow seemed to come down pretty quickly - it all happened in a short space of time."
Three flights - an Aer Lingus flight and two Aer Arann flights - were cancelled this morning due to the poor weather conditions.
The main runway running east to west at the airport lies in a very exposed area of north Dublin. Conditions on the busy back roads around the airport were also bad this morning.
Motorists were warned to continue to take extreme care on the roads today as snow and high winds hit many parts of the country.
Snow has stuck in many areas and accompanied with black ice has made some roads treacherous. The north, northwest and southwest are the worst affected. Parts of Sligo, Donegal, Leitrim and Longford are particularly hard hit.
Further snow is likely especially in Connacht and Ulster today. Very high seas in excess of 10 metres are also expected along Atlantic coasts, which could cause coastal flooding.
Motorists are urged to drive with care on all routes and to reduce speed.
The busy N7 Naas road was treacherous with black ice this morning, particularly from Citywest to Rathcoole.
In Dublin, DART and rail services are running to schedule, and Bus Éireann and Dublin Bus services are operating as normal. However, there were long delays early this morning on some main routes, including the N3, as motorists steered clear of treacherous back roads.
In the North, there has been traffic disruption. The Glenshane Pass on the road between Belfast and Derry saw one of the worst snow falls, with motorists urged to take extreme caution along the route.
The main road between Armagh and Keady was temporarily closed after a number of vehicles became stuck in snow.
Dozens of schools were also closed, while power lines were also brought down by windy conditions in Toombridge, Co Antrim. There were delays to some flights at Belfast City Airport and two flights to London Heathrow were cancelled.