More work is needed to reduce flight disruption despite an improvement in punctuality in the spring, according to the Civil Aviation Authority.
All 10 airports monitored by the regulator saw increases in on-time performance and falls in average delay.
Heathrow was the worst-performing airport in the second quarter of the year, with just 77% of flights operating on time against 79% at Gatwick.
Birmingham registered the biggest increase in scheduled flight on-time performance of six percentage points.
The new CAA figures show that 81% of all scheduled flights and 77% of charter flights were on time in the period.
This represented an improvement of three percentage points for scheduled flights but the charter figure was the same year on year.
The average delay at London area airports fell by two minutes to 11 minutes between the second quarter of 2012 and the same quarter in 2013.
But the average delay across all charter flights was 18 minutes, an increase of one minute.
CAA regulatory policy group director Iain Osborne said: “All passengers using UK airports are entitled to expect their flight to get them to their destination on time, so it’s pleasing to see that punctuality has improved.
“However, these figures also show that many passengers still experienced delays this spring, so there is clearly more work to do to minimise disruption.
“We therefore want to see airlines, airports and air traffic control building on recent performance and working together to further increase flight punctuality and improve the experience of passengers flying in and out of UK airports.”
There were 356,000 scheduled and 20,000 charter passenger flights at the 10 airports in the quarter. This represented a 1.6% increase in scheduled flights and a 2.6% rise in charters against the same quarter in 2012.
Flights to and from Luxembourg recorded the best on-time performance of 92.6% and the lowest average delay of 4.5 minutes.
Services to and from Tel Aviv suffered the lowest punctuality with an on-time performance of 65.9% and the highest average delay of 17.9 minutes.