Flights have been redirected away from Birmingham Airport following a technical fault.
Arrivals were suspended after a power failure affected a radar facility operated by National Air Traffic Services (NATS).
Over 20 inbound flights were cancelled or diverted and several flights were delayed by over four hours.
Disruption has continued into this morning as three outbound flights to Amsterdam, Frankfurt and Paris have been suspended.
NATS has apologised for the disruption, explaining the outage was caused by severe weather in the area.
The organisation said last night its engineers were working alongside National Grid to restore full service as quickly as possible.
Inbound flights were diverted to alternative airports, including East Midlands Airport and Liverpool John Lennon Airport.
In total, nine flights were cancelled or rerouted, while at least 12 others experienced delays.
A Birmingham Airport spokesperson said last night: 'Due to a technical issue with NATS' radar that serves Birmingham Airport, only departing flights are currently operating, with some delays.
'All arriving flights are currently suspended. We apologise for the delay to customers, and we are working closely with NATS to rectify the issue.'
Power was restored to the radar which serves Birmingham Airport shortly before 1.30am this morning.
Under passengers' rights rules, travellers whose flights are cancelled are entitled to be flown to their destination as soon as possible on any airline and be provided with meals and hotels until they arrive.
However, they will not receive compensation for the delays.
Power–related failures have previously caused widespread disruption at UK airports.
In March last year, a power outage at Heathrow Airport led to the cancellation of around 1,300 flights and affected more than 270,000 passengers.
An investigation later concluded that the incident was triggered by a catastrophic equipment failure at a nearby electrical substation.
NATS also faced criticism last year after air traffic control issues forced the cancellation of more than 1,000 flights departing from UK airports, drawing frustration from airlines and travellers alike.
