Around 80 flights have been cancelled in and out of Heathrow as a result of bad weather.
Airport operator BAA said about 50 departures and 29 arrivals were called off yesterday because of high winds and thunderstorms.
The first cancellation was at about 6.30pm and a number of airlines were affected.
A BAA spokesman said: "There were cancellations due to the high winds and isolated thunderstorms.
"We were advising passengers who hadn't yet arrived at the airport to check the status of their flights."
He said there were "some delays" to flights, but stressed the timetable had returned to normal by about 9.30pm.
BAA expected the schedule to be "running fine" today, he added.