More than 70 flights to or from Heathrow Airport in London have been cancelled following snowfall in parts of Britain.
The flights affected are mostly on short-haul routes, although British Airways services to New York and Chicago were among those affected.
Forecasters in the UK have said that much of eastern England and Scotland had been hit by snowfall overnight.
Meanwhile, Met Éireann has issued a Status Yellow snow and ice warning for Ireland this weekend.
There will also be snow showers but some areas will stay dry, especially the northwest.
The warning is in place from midday until 9am on Monday.
Met Éireann said it will be very cold this weekend with wind chill and icy patches.
As St Patrick's Day parades get under way across the country, showers will progressively turn more wintry.
Most of the showers will be in the east, but a few will reach the midlands and south as well.
There will be some accumulations of snow on high ground at first, but on lower levels later as well.
Separately, a Status Orange snow and ice warning for the east and southeast was issued by Met Éireann for tomorrow.
The Orange alert is for counties Dublin, Kildare, Louth, Wexford, Wicklow, Meath and Waterford.
Scattered heavy snow showers are expected along with some "associated drifting", according to Met Éireann.
The warning comes into effect at 3am tomorrow and will remain in place until midday.