A severe weather warning is in place for heavy snow showers across parts of Counties Londonderry, Antrim and Down on Sunday night.
A further 5cms is likely in places and possibly as much as 10 cms locally especially towards the north.
Travel in and to Northern Ireland has been affected on Sunday.
Northern Ireland's airports are open, as are Dublin, Cork and Shannon, but are experiencing a high number of cancellations and delays.
The Roads Service warned that driving conditions were still hazardous with overnight snow leaving a risk of ice.
Ulsterbus services have been severely disrupted and subject to cancellations.
On Sunday night, the south and west should stay dry and clear with temperatures maybe as low as -15 or -16C in one or two rural areas.
It will be very icy, particularly over frozen and compacted snow, with a severe frost and some freezing fog patches are likely in places as well.
Driving conditions are expected to be treacherous again for the Monday morning rush hour and there is also the possibility of freezing fog.
Roads Service staff carried out salting and snow-ploughing operations throughout Saturday night and into Sunday morning.
The three Northern Ireland airports have advised passengers to contact their airlines before travelling because of the knock-on from Friday and Saturday.
Gatwick had hundreds of people sleeping in its terminals on Saturday night, Heathrow thousands.
No flights are landing in Heathrow on Sunday and very few are taking off - none of them to Northern Ireland.