Passenger volumes using Heathrow in November exceeded 6 million for the first time.
Numbers rose by 3.3% to 6.11 million passengers, with North American routes seeing 5.8% growth because of more competitive pricing, according to the London hub.
The Africa region saw the biggest percentage increase, up 10.2%, driven by new routes to Marrakech, the Seychelles and Durban.
However, Middle East and UK domestic traffic both fell over the same month last year.
Last month saw additional domestic services were announced, with Heathrow gaining a Flybe link to Newquay in Cornwall for the first time fro March 2019.
British Airways will add a new daily service to Inverness, set to boost Scotland’s economy by up to £17 million.
Heathrow became the first UK airport to set out plans for carbon neutral growth, outlining the role it will play on four key areas to reduce and offset carbon emissions from the growth in flights, created by an additional runway.
Heathrow chief executive John Holland-Kaye said: “Record numbers of passengers are choosing to use Heathrow because we offer outstanding service and better value for our passengers.
“But growth must be sustainable, and our blueprint for carbon neutral growth is an important step towards our ultimate goal of zero carbon aviation.”