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.”
