Rain later replaced snow across the region but local gusts continued to affect the seaside on Tuesday night, with severe winds reaching 65mph in some areas along the north coast and north Down coast.
A MET Office yellow weather warning remained in place until midnight, when winds were expected to die down.
"The public should be aware of the potential for disruption, with winds strong enough to bring down some trees," a spokesperson said.
The Roads Service carried out widespread salting on the road network as overnight snow, wintry showers and strong winds hit the region.
Snow ploughs were used in some of the worst affected areas including Newry, Craigavon and the Craigantlet Hills in Belfast.
Motorists experienced traffic disruption amid icy conditions on Tuesday morning, with a number of crashes reported on the M1, at Blacks Road westbound off-slip, and on the A55 Upper Knockbreda Road in Belfast.
In Co Down, a bus became stuck in snow on Ballynahinch Road in Downpatrick. The road was closed at Listooder Hill at the junction with Cahard Road.
Flights operated as normal at Belfast International Airport and George Best Belfast City Airport.
Translink says its Metro services in Belfast are now running as normal after earlier delays.
Elsewhere, the Southern Education and Library Board was badly hit by schools closures.
In the Newry area, the following schools were closed on Tuesday: St Joseph's Covent Primary School, Cloughoge Primary School, Mullaglass Primary School, St Patrick's Nursery and Primary School, St Malachy's Primary School, Carnagat, St Joseph's Boys High School, Our Lady's Grammar, Sacred Heart Grammar, St Mary's High School, and Abbey Christian Brothers Grammar.
In the south Armagh area, the following schools were closed: St Patrick's Primary School, Cullyhanna, St Michael's Primary School , Newtownhamilton, St Mary's Primary School, Granemore, Darkley Primary School, Dromintee Primary School, Killeavy, Drumhillery Primary School, Middletown, St Oliver Plunkett's Primary School, Forkhill and St Paul's High School, Bessbrook.
In the south Down area, the following schools were closed: Holy Cross Primary School, Attical (Kilkeel), St Patrick's Primary School , Drumgreenagh, Castlewellan Primary School, Castlewellan, Brackenagh West Primary School, Kilkeel, Moneydarragh Primary School, Annalong, Clontifleece Primary School, Warrenpoint, St Patrick's Primary School, Mayobridge and St Mark's High School, Warrenpoint.
A national warning for gale force winds was also put in place in the Republic of Ireland.
MET Éireann said it was "very cold and extremely windy today, with frequent showers, many of them falling as hail, sleet and snow during the morning, with a risk of blizzard conditions in places, but turning to rain and hail during the day, with any lying snow melting."
Scattered thunderstorms were also expected with strong to gale force westerly winds, veering northwesterly and gusting to between 75-110km/h.
On Tuesday night, sleet showers were expected mainly over high ground in the north and northwest, with frost and a risk of icy stretches.