March, April and May were the busiest in Heathrow and Edinburgh airports’ history, according to BAA’s latest figures.
Heathrow Airport handled 5.9 million passengers last month, while Edinburgh Airport handled 826,000.
Traffic at BAA’s six airports increased by 9.2% on last May to 9.3 million passengers, although the airport operator said the figures were skewed by last year’s figures that were affected by volcanic ash and industrial action.
Taking into account the negative effect of events in 2010, the group has an underlying growth of 1.7% year-on-year.
Traffic at Aberdeen and Glasgow airports increased 7% in May, while Southampton saw a decline in traffic of 1.1% compared to May 2010.
Stansted saw passenger numbers grow 0.7%, in its second consecutive monthly rise for the first time since October 2007.
However, BAA said that in the year to date Stansted was experiencing an annual decline of 4%, due to low-cost airlines transferring capacity to continental Europe.