Heathrow traffic rose 6.7 per cent to almost 6.2m in the month, with a big increase in trips to the Middle East and Asia.
In the past year, passengers numbers at Britain’s busiest airport rose 3.7 per cent to 72.8m.
And planes took off with more seats filled, with an average flight now leaving or entering Heathrow with 161 passengers onboard.
The airport also reported a 4.4 per cent rise in cargo volumes, following a rocky few years for air freight transport.
Meanwhile, Stansted Airport took 10.7 per cent more passengers in April, and its traffic in the past year is up 3.4 per cent to 18.2m. New owner Manchester Airports Group said the rise “is encouraging and highlights the important role that airports like Stansted and Manchester will play over the next 10-15 years”.
Last week, Gatwick reported a 15.4 per cent boost in April traffic.
Heathrow and Gatwick will today outline their final submissions to the Davies Commission on their proposed new runways.