A second cold spell is gripping the country with Connacht, Ulster and west Munster facing the worst of the snow and ice.
Severe weather warnings are in place with heavy snowfalls reported in Northern Ireland, especially in the greater Belfast area.
Northern Ireland has seen 'probably' its worst snowfalls in 25 years over the last 24 hours, according to meteorologists.
Extreme weather has forced the closure of more than 700 schools today.
Belfast International Airport has suspended all flights due to severe snow storms. A statement from the airport says flights are suspended until at least 9pm. Aer Lingus and easyJet flights have been cancelled for the remainder of the evening. Passengers are advised to check with their airlines before travelling.
Belfast City Airport will remain closed for the rest of the day.
City of Derry Airport has been closed until tomorrow morning. A notice on its website said it planned to resume normal operations from 8am.
Snow showers are expected to become more widespread tonight with accumulations of up to 5cms in some areas. Temperatures will drop to as low as -7C and there will be a severed widespread frost with icy stretches on roads.
Snow showers tomorrow will be largely confined to coastal areas of the east, north and west of the country with lows of -1C.
Low salt supplies around the country mean that priority will be given to primary routes, with many local authorities warning that secondary roads may not be treated at all.
Road conditions in the Midlands are treacherous in many areas after heavy and prolonged snow showers.
Motorists in Longford, Athlone, Tullamore and Mullingar are advised to take care due to snow showers.
AA Roadwatch has said snow is falling onto already very icy roads in many areas nationwide, and extreme care is advised.
Among the counties worst affected are Donegal, Sligo, Mayo, Galway, Leitrim, Cavan, Monaghan, Longford and Roscommon.
Main roads are said to be passable but conditions on secondary and back roads are likely to be more dangerous.
Gardaí in Galway say 2cm of snow fell overnight around the county and roads are described as treacherous in some areas because of freezing.
Areas like Athenry and Claregalway are particularly bad. Roads around the city and county have been gritted and the motorway between Galway and Dublin is passable.
A spokesperson for Mayo County Council said all main roads have been treated and are passable but extreme care is advised, and is using salt to treat national roads and the access road to Knock Airport.
Ordinary grit will be used on regional routes in order to conserve salt supplies that are running low.
There is enough in stock to keep going for another week. Further deliveries are promised from the NRA, which would provide enough cover into the middle of next January.
Blades are are also being fixed onto lorries to make grit more effective.
Gardaí are advising drivers to take great care if they have to journey out, while the Police Service of Northern Ireland is advising motorists not to make any journeys unless extremely necessary.
Iarnród Éireann says all services are running to schedule so far this morning.
Bus Éireann says there is no indication of any disruption to services at the moment, but added that the situation is being constantly monitored.
The company says it will try to maintain as many services as possible and in terms of school bus services, decisions are made locally as to whether they will run. Local schools usually text parents regarding transport.
Sean Murphy of Chambers Ireland said as long as roads remain gritted, shops will continue to do business.
Amsterdam Airport Schiphol was also affected by the adverse weather across Europe. Aer Lingus cancelled two flights scheduled to depart for Amsterdam from Cork and Dublin.
The airline is warning that it expects further disruption because of severe weather across Continental Europe.
There is no snow at Shannon Airport and all flights are on schedule.
At Ireland West Airport in Knock, some early morning flights were cancelled after 8cm of snow fell overnight. However, the airport is operating again although some delays may be experienced.
Met Éireann | AA Roadwatch | Schooldays.ie (for information on school closures) | Iarnród Éireann | Luas | Bus Éireann | Dublin Bus | Citylink | Dublin Airport | Cork Airport | Shannon Airport | Ireland West Airport (Knock) | Belfast International Airport | Belfast City Airport | Alone | Age Action Ireland | Dublin City Council Traffic Cameras | Aircoach | Tap Tips
