The UK's biggest airport was helped by an end to the Icelandic volcanic ash disruption and a temporary cessation in industrial action by British Airways cabin crew.
We have been saying for a while that we would have had good figures if
had not been for the volcanic ash or BA industrial action
A further boost to Heathrow came from continued strong traffic from overseas visitors and the fact that it remains a crucial transfer hub for long-haul flights that start outside the UK.
However, other airports are not faring as well. Stansted saw a 7.2% slump in passenger numbers to 2.02 million in July.
Aberdeen airport suffered a 4.1% drop in passengers, slightly worse than 3.6% fall at Glasgow.
"Heathrow is definitely more resilient because of the hub nature of the airport for passengers who use London to transfer to other destinations," a BAA spokesman said.
"We have been saying for a while that we would have had good figures if had not been for the volcanic ash or BA industrial action. However, we are not yet out of the woods."
