Gatwick Airport was forced to cancel 13 flights yesterday after a massive power cut shut down parts of the South Terminal.
Other flights were delayed by around an hour as airport staff struggled to communicate with passengers using loudhailers and white boards.
EasyJet flights were switched to the North Terminal yesterday afternoon, but the airline said normal operations were resuming today.
A Gatwick spokesman said that out of 361 flights, 13 were cancelled yesterday and there were some delays of around an hour.
Stranded passengers are not likely to be able to claim compensation from the airlines under EU regulations as the cancellations and delays could be considered "extraordinary circumstances" for which the carriers would not be responsible.
