Heathrow saw a 1% rise in passenger numbers in July and August once the effect of last year’s London Olympics was stripped out.
Numbers hit 6.96 million in August with load factors up even though airlines introduced larger aircraft.
The increase would have been 7.7% without the impact of the 2012 Games when numbers fell.
The number of passengers on each flight rose 6.9% to 168.9, resulting in an average load factor of 82.7%, up 2.6 percentage points on August 2012.
Traffic was up by 13.4% to the Middle East and central Asia, while China was up by 28.3% and India by 18.7%.
European traffic as strong, showing growth of 8.6% including rises to Italy, France and Germany.
Chief Executive Colin Matthews said: “Larger, fuller aircraft continue to contribute to rising passenger numbers at Heathrow.
“However, don’t imagine this will solve the UK’s hub capacity crisis. The country is falling behind its international rivals in links to emerging economies – which in turn means we’re losing the global race for jobs, trade and economic growth.
“Only a larger hub airport can put the UK back at the forefront of international connectivity.”