Two million British holidaymakers are set to travel abroad in the first weekend of the summer holidays for the majority of schools in England.
The best July weather in the UK for years has also boosted domestic bookings, with operators reporting strong demand and a rise in last-minute bookings.
The Channel Islands, Lake District and traditional seaside resorts of Blackpool, Bournemouth and Brighton are among the most popular domestic destinations.
Spain remains the top overseas country for holidaymakers with the Balearic and Canary Islands selling especially well, according to Abta.
Other Mediterranean destinations, especially Greece, Turkey and Tunisia, are also high on the list.
Mexico and Cuba have sold well, with Florida remaining the number one long-haul choice for families.
Airports in the southeast of England are expecting a busy weekend with 480,000 passengers departing 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.
Manchester will handle 160,000, with 66,000 flying from Birmingham, 70,000 from Newcastle, 50,000 from Bristol and 30,000 from Leeds/Bradford.
Other regional airports, ports and the channel tunnel are also expected be extremely busy over the weekend with hundreds of thousands leaving the country.
Eurostar is reporting an increase in passengers 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. ”