Around two million Britons will head overseas this weekend as the school summer holiday getaway begins in earnest.
Spain and its islands, including Majorca and Tenerife, remain the number one destination for those seeking overseas sun.
But the recent heatwave in the UK has led to a boost in domestic bookings, with holidaymakers flocking to the Channel Islands, Lake District and the traditional seaside resorts of Blackpool, Bournemouth and Brighton, said travel organisation Abta.
The Mediterranean destinations of Greece, Turkey and Tunisia have also sold well, while Florida, Mexico and Cuba are popular spots for those on long-haul trips.
Airports in south east England are expecting a very busy weekend, with about 480,000 passengers likely to depart from Heathrow, 276,000 from Gatwick, 125,000 from Stansted and 70,000 from Luton.
More than 100,000 will be leaving from Scottish airports, with 50,000 from Glasgow alone, while 160,000 are due to depart from Manchester, 66,000 from Birmingham, 70,000 from Newcastle, 50,000 from Bristol and 30,000 from Leeds Bradford.
Other regional airports, ports and the Channel Tunnel will also be extremely busy over the weekend with hundreds of thousands of people leaving the country.
High-speed Channel Tunnel train company Eurostar is reporting an increase in passenger numbers on last year with 70,000 heading off to Paris and the south of France over the weekend.
Abta chief executive Mark Tanzer said: "This weekend sees the start of the main summer holiday getaway and it's one of the busiest of the year. Millions of holidaymakers will be heading off overseas with the Mediterranean countries attracting the lion's share of visitors.
"The recent amazing weather at home has also given a great boost to domestic tourism and many Abta members are reporting a surge in last-minute bookings for holidays throughout the UK. "