Abta says strong sales on the Balearics, mainland Spain, Greece and Florida would account for many journeys, as well as Turkey where the weak lira against the pound is offering British holidaymakers “extremely good value”.
Barcelona, Dublin, Prague, Paris and Amsterdam, meanwhile, are expected to be go-to city break options.
And despite a mixed forecast, British coastal resorts, cottages and campsites are also likely to be busy.
In total, the association estimates some 2.2 million Brits will make a getaway over the weekend, while the CAA said 32,000 flights would depart UK airports over the weekend.
Around 600,000 people will depart London airports alone, with Heathrow likely to handle 308,000 passengers, Gatwick 192,000 and Stansted 108,000.
Manchester will welcome 220,000 passengers, Edinburgh 98,000, East Midlands 77,000, Bristol 58,000 and Southend 13,000.
Hundreds of thousands more will make for Europe from ports, the Channel Tunnel and Eurostar.
Mark Tanzer, Abta chief executive, said: “The August bank holiday is one of the busiest of the year as we near the end of the summer and the school holidays.
“Temperatures around the Mediterranean are no longer at the record-breaking temperatures we saw last month and sunshine is virtually guaranteed.
“Many people will also be making the most of what the UK has to offer, taking weekends away or longer holidays to our coasts and countryside.
“As always at busy times of year for travel, if you are driving leave a little extra time to get to your place of departure and if using public transport check in advance for engineering works.”
The CAA has backed Abta’s advice, advising passengers allow time to get to airports. It has also called on holidaymakers to stick to their limits and avoid over-indulging before flights after it revealed earlier this month incidents of in-flight drunken behaviour are likely to hit record highs this year.
“The CAA continues to remind passengers drunken and abusive behaviour at an airport or on an aircraft is totally unacceptable and offenders can face a sentence of up to five years in jail,” said the authority in a statement.
CAA director Richard Stephenson added: “The aviation industry will be working hard this weekend helping everyone going on holiday to have a trouble-free journey.
“We therefore call on all passengers to act responsibly as drunken and abusive behaviour is totally unacceptable. Not only does it cause distress to fellow travellers, but it can jeopardise flight safety.
“Passengers need to know they will face the full weight of the law should they be found guilty of disorderly behaviour.”