The floors of all the terminals were littered with bodies, stretched out under those foil sheets handed out after marathons. Under them lay people desperate for sleep, many after two nights on the hard, cold floor still with no idea when, if ever, they would escape from merry holiday plans which had turned into an apparently unending nightmare at Heathrow airport.

An estimated 400,000 passengers were due to fly from Heathrow over the weekend. None got away, although a handful of flights were due to land tonight. Although the airport hopes to resume flights tomorrow, inevitably some will not get away before Christmas – especially those being told by their carriers to rebook their places on to planes which are already packed on the last days before the holiday.

Heathrow, which had announced confidently on Saturday morning that overnight snow and ice-clearing had kept the runways clear – convincing many intending travellers to head for the airport – was by far the worst hit. Gatwick airport was open again, although there were long delays on many flights. Belfast airport reopened today, after the worst snow across Northern Ireland in a quarter of a century. Stansted, Luton, Exeter, London City, Birmingham, Bristol and Southampton were all badly affected.

The unanimous complaint from the stranded passengers was not their hideously uncomfortable nights on the airport floor, but the lack of any up-to-date and accurate information.

Most had been given no information by the airports authority, BAA, except a plea to leave the airport, or at least contact their airlines. The latter suggestion brought many who had been trying to do just that for hour after hour, holding on payphones with anxious queues behind them, or on mobile phones with failing batteries and credit, to snarling point. Many were getting the best information in phone calls from family members thousands of miles away.

Jonna Lehto, who has been working in London at a restaurant, was trying to get home to Finland and incredulous at the scene which met her at the airport. "I really can't comprehend this. This is the first time in my life I have had to come to grips with disruption like this and I am used to flying in very awful weather."

If she can just get back to Helsinki, she is confident she will have a choice of road, rail or bus travel back to her home in south-east Finland, where the temperature is a mere -22C.

Kevin Ulrich was equally contemptuous: "It's no more than a sneeze, it's hardly snow at all." He is bound for Anchorage, Alaska, where they pay no attention to snow until it's at least a metre deep.

In a statement, BAA said the decision had been taken "reluctantly" to close for the day even though one runway was clear. The change in temperature overnight had led to a significant buildup of ice on parking stands, it said.

Ulrich was in a large group of US students who arrived early on Saturday morning and have since built a superbly organised fortified compound out of luggage trolleys in Terminal 5, where they bedded down on foam mats, their coats, any blankets they could scavenge, and the yellow plastic trays for oversize baggage, which turned out to be just long enough to stretch out in.

Ulrich, who estimates he has slept for three of the last 51 hours and was becoming swivel eyed, stood lookout through the night, guarding their baggage. On their second full day at the airport there were some tears: one member of the group was missing her family Christmas, another was celebrating her bleakest birthday ever, and another was due to sing the solo in his church carol service.

The planned journeys and their routes to the airport varied wildly, but the various stranded travellers shared a single view of what had happened. The snow dumped on the capital on Saturday may have been an act of fate, but it was accurately forecast and so entirely predictable. The almost complete failure to supply information about what was happening, however dismal the news, caused more rage than the disappearing airline desk staff, the foil "blankets" – cloth ones were reserved for children – the refusal to help with hotel bookings, the £8-a-bag luggage stores which were full within hours of the first cancellations on Saturday, or the sandwiches and water distributed – the cynical American students said – only when a television camera appeared.

In Terminal 5, the first and worst affected terminal when British Airways was the first to abandon all flights on Saturday, the departures board listed columns of flights. Each had an information phone number beside the flight number: it took several visits to the departure board before it dawned on travellers that all the phone numbers were identical, and all led to an identical recorded message: "All our lines are busy. For the latest information or to change travel plans, please visit BA.com." "These idiots think the whole world is surgically attached to an iPhone," one Canadian woman snarled.

Anna Gracie, who spent eight hours on Saturday sitting on a BA plane with her four-year-old child before the flight, to Abu Dhabi, was cancelled and passengers marched back to the terminal, said: "I won't be booking any more flights with BA ever again and in all honesty Terminal 5 is an utter disgrace."

Some of the stranded had come as early as Friday afternoon, some were still turning up on the spluttering Piccadilly line tube – the Heathrow Express train service was cancelled. All found it virtually impossible to get accurate information before travelling. Dineke Tenhove's experience was typical: she left home in Leicester at 7am today, when her group's flight to Senegal via Portugal was still listed as "scheduled".

At one point the driver of the coach threatened to turn back, because conditions on the motorway were so bad, and he eventually took his passengers to Victoria coach station instead of the scheduled airport drop.

She finally reached Heathrow at 1.30pm, to be met by BAA staff turning people back in the underground tunnels from the tube, repeatedly announcing: "There's no flights going anywhere – just go back and contact the airlines."

"I just felt I had to come unless somebody definitely told me not to," Tenhove said. "If there was only one flight out of Heathrow today and it was mine and I wasn't on it, I'd be in despair."

At Paddington, there were chaotic scenes as both the Heathrow Express and the Heathrow Connect services to the airport were suspended.

Bemused travellers were greeted with several large hand-written signs stuck on to the Heathrow Express information booth, reading "Airport closed", while an electronic display board above platforms six and seven flashed "cancellation" against the majority of flights.

Back at the airport, the calmest man in Heathrow, and possibly the world, was Michael from Oxford, a psychotherapist (reluctant to give his surname to protect his patients) and a credit to his profession. He was installed on an elegantly spread foil blanket, his laptop balanced on his cabin bag, at his side the food, water and toilet roll he brought when he left his home in Oxford at 5pm on Saturday afternoon expecting to end the day with a late supper in Crete.

Then a Red Cap porter approached, and said he was sorry, but it was dangerous to sleep on trolleys. Michael explained that he wasn't sleeping, he was working, but that an entire family of five had slept on the trolley the night before. "I'm sorry sir," the porter said, but insisted on removing the trolley.

For a moment, as he gathered up his possessions and rejoined the groundlings wondering if they will ring in the new year never mind Christmas at the airport, Michael's zen-like calm almost shattered.