Scores of flights in and out of Manchester and Leeds Bradford airports have been cancelled due to severe weather.
More than 40 departures and arrivals have been cancelled at Manchester Airport so far today, while 22 flights in and out of Leeds-Bradford have also been cancelled.
But many flights in and out of the two airports have taken place and further flights today have been scheduled.
Travellers are also advised to contact their airline for further information, particularly if they are flying to Ireland and Scotland.
Hundreds of flights to Dublin, Edinburgh and Glasgow have been cancelled as Storm Emma and the Siberia weather system (the Beast From The East) continues to make takeoffs and landings unsafe.
A spokesperson for Manchester Airport said: "We’re continuing to monitor the adverse weather here at the airport.
Passengers are advised to check the status of their flight with their airline.
Passengers should also leave additional time to get to the airport due to potential issues on the road and rail networks caused by the snow."
There is additional information here on what to do if your flight is cancelled or delayed or you miss your flight .
A spokesperson for Leeds-Bradford Airport said: "As a result of adverse weather conditions, Leeds Bradford Airport is presently experiencing delays.
"We recommend you contact your airline or tour operator and check the status of your flight before arriving at the airport.
"You can also check the latest flight information by viewing our arrivals and departures page here .
"Please allow additional time for your journey to Leeds Bradford Airport."
Airlines were asked to reduce their flights at the west London hub following discussions with airport officials and air traffic control provider Nats.
The high demand for slots at Heathrow means there's very little slack during normal operations and therefore the number of flights has to be cut during disruption, reports the Manchester Evening News .
Dublin Airport will see at least 331 cancellations on Friday, and 95 planned Edinburgh Airport services will not operate.
The number of Friday cancellations stands at 67 at Glasgow Airport, which was closed on Wednesday and Thursday.
Almost 5,000 flights have been cancelled to or from European airports since Tuesday, meaning many UK travellers are now stranded abroad.
A spokesman for travel trade organisation Abta said: “Customers who are overseas and whose flight arrangements are delayed or cancelled should liaise with their tour operator or airline regarding changes to their travel itineraries and new flight arrangements.
“If their flight is in the European Union or their airline is an EU carrier, customers will be entitled to food, refreshment and overnight accommodation or a refund of proportionate costs and will be flown home as soon as is possible at their airline’s expense.”