LONDON — Thunderstorms caused severe delays for hundreds of flights at London's Heathrow and Gatwick airports on Saturday. More than 600 flights scheduled to land or depart from these airports experienced delays, with dozens of flights ultimately canceled.

Some delays extended beyond six hours, and passengers were held on grounded planes for multiple hours. London experienced heavy rain and thunderstorms overnight, following two days of temperatures exceeding 30 degrees Celsius.

FlightAware reported that at least 367 flights at Heathrow and 352 flights at Gatwick were delayed on Saturday. Nats stated that further disruption was anticipated throughout the day due to forecasted severe weather across the south-east of England.

British Airways acknowledged adjustments to its schedule due to air traffic control restrictions caused by adverse weather. "Like other airlines, we've had to make some adjustments to our schedule today due to air traffic control restrictions caused by adverse weather conditions affecting parts of UK airspace," British Airways stated. "While the vast majority of our customers will be unaffected, we apologise for the inconvenience caused and our teams are working hard to help those impacted get their journeys back on track."

EasyJet confirmed it had preemptively canceled some flights to and from Gatwick in advance of the thunderstorms. "We are doing all possible to minimise the impact of the weather disruption for our customers and are notifying passengers in advance with their options to rebook or receive a refund as well as hotel accommodation and meals where required," EasyJet stated.