On the busiest day of the year for air traffic in Europe, thousands of passengers are enduring long delays – with some easyJet passengers at London Gatwick and Manchester learning their flights were cancelled only hours before they were due to depart to Continental Europe and the Mediterranean.

EasyJet has so far grounded at least 10 flights to and from the UK. Passengers to Palma from both Manchester and Gatwick were told in each case “a technical issue with the aircraft could not be resolved”.

Flight cancellations from Manchester to both Amsterdam and Paris were blamed on “adverse weather conditions in Berlin”. A number of departures from the German capital were grounded on Thursday evening.

No reason was given by easyJet for the Gatwick-Naples cancellation.

The corresponding five inbound flights are also grounded.

In all cases it appears that passengers were notified between 3am and 4am – by which time they were at, or travelling to, the airport.

Under air passengers’ rights rules they are entitled to be flown to their destination today, but the final Friday in June is always one of the busiest days of the year for travel and finding seats on any airline will be challenging.

For many Wizz Air passengers, the problem is extreme delays.

Nearly 200 Wizz Air passengers who were due to fly home from Sicily to Gatwick on Wednesday finally took off on Friday morning after a technical delay.

Among the passengers on Wizz Air flight 5794 from Catania was the ITV News reporter Joe Coshan.

He told The Independent: “We were due to fly home at 11pm on Wednesday night from Catania. By the time we’d got to the airport, it was delayed until midnight. But we didn’t even board the plane until then.

“After spending an hour on the plane, we were told there was a problem with the plane, an engineer deemed it not safe to fly and we would be put on a plane in the morning.”

At this point all passengers should have been provided with hotel rooms. But while some, including Mr Coshan, booked their own hotels, others were told there was no accommodation.

The flight was originally rescheduled for 1pm on Thursday, which then moved to 8pm. Passengers were told they would need to spend another night in Catania and the flight would depart at 6.30am on Friday. The aircraft finally took off at 7.15am.

Wizz Air has some extreme delays at its London airports, with an early flight from Gatwick to Podgorica in Montenegro currently seven hours behind schedule and a Luton-Prague flight with a 12-hour delay.

Three Thursday evening departures from Luton to airports in the Balkans – Varna in Bulgaria plus Bucharest and Cluj-Napoca in Romania – finally took off after 2am on Friday, with knock-on delays for today’s flights.

Eurocontrol told The Independent on Thursday that the network “is experiencing the impact of severe convective weather covering the central and southeastern areas”.

Friday 28 June 2019 was the busiest day in Eurocontrol’s history, and the corresponding date five years later was expected to see more flights than on any other day in 2024.

The Independent has asked easyJet and Wizz Air for responses.