Heathrow managed marginal passenger growth in January despite a period of disruption from low visibility and snow.
The airport reported a 0.3% rise to a record 5.18 million passengers over the same month last year.
Domestic traffic slumped by almost 6% but European numbers were up by 1.8%.
North American traffic continued a recent “robust” performance, up 2.2% and Middle Eastern traffic rose 3.3%.
Of the emerging BRIC economies, passenger numbers were up 14.1% to China and 7.1% to India, but down 4.1% to Brazil and 2.7% to Russia.
Heathrow’s load factors – showing how full the average flight was – set a record for January at 70% – up 2.1 percentage points on January 2012.
Domestic traffic was down 5.8%, however European traffic was up 1.8%.