The Department for Infrastructure has said salting of the scheduled road network has been ongoing throughout the night, with snow ploughs also operating where necessary.
The DfI said this morning: “The south and east of the province are experiencing the most snow with much of the M1 and A1 currently down to one lane in each direction. Further salting and ploughing is continuing at present.
“In Counties Down and Armagh the main roads at present are passable with care, but snow is continuing to fall and conditions will possibly become more difficult as the morning commute starts.
“Motorists should exercise caution when travelling this morning as driving conditions, particularly in the south east of the province, are very difficult.”
Meanwhile Translink has warned of possible delays/disruption on the Bangor-Portadown line due to “poor rail conditions”.
Tranlink also said there are no bus services leaving Banbridge or through Banbridge from Newry, Portadown or Lurgan, Rathfriland.
“We will review this after 9am,” said Translink.
Belfast City Airport remains opens but warned that “heavy snow in England is causing delays to some flights in/out of the airport and some early flights to/from Scotland have been cancelled”.
Some flights were also delayed and cancelled at Belfast International Airport who reminded passengers to check live flight information online.