Heathrow handled a record 262,000 passengers on the airport’s busiest-ever day on August 4.
A total of 7.7 million people used the capacity constrained London hub last month, up 0.1% on the same month last year.
However, numbers fell to EU countries, the Asia-Pacific region and Middle East.
Flights to and from Africa saw the most growth last month, with a rise of 6%, helped by a new British Airways route to Durban and increased capacity to Nigeria.
UK domestic flights grew by 2.7%, with more passengers using services to Newquay, Guernsey and Isle of Man for summer staycations.
The Department for Transport unveiled plans for all major UK airports to implement CT scanning technology which could bring an end to the 100ml liquid restrictions and potentially end the need for liquids bags, reducing the amount of single-use plastic attributed to aviation.
This followed Heathrow announcing plans to invest £50 million in cutting edge CT scanners.
Heathrow CEO John Holland-Kaye said: “We are continuing to invest in future-proofing Heathrow.
“The airport will be a test bed for ground-breaking technology like our new CT scanners to ensure that our passenger experience remains world class as numbers continue to grow.
“Using new technology and innovation as we deliver expansion will also demonstrate our global leadership on sustainable travel.”