Heathrow Airport closed completely until midnight with 1,300 flights cancelled

Heathrow Airport is closed today (21 March) until midnight with more than 1,300 departing and arriving flights disrupted.

A nearby fire at North Hyde electrical substation has caused a power outage, impacting thousands of homes with around 150 people evacuated.

Heathrow - which is the UK's largest airport - said it was among those impacted by the power outage.

Online flight tracking service FlightRadar24 estimated that the closure would affect at least 1,351 flights to and from the airport in West London.

A Heathrow spokesperson said: “Heathrow is experiencing a significant power outage across the airport due to a large fire at a nearby electrical substation. Whilst fire crews are responding to the incident, we do not have clarity on when power may be reliably restored.

“To maintain the safety of our passengers and colleagues, we have no choice but to close Heathrow until 23h59 on 21 March 2025. We expect significant disruption over the coming days and passengers should not travel to the airport under any circumstances until the airport reopens.

“We will provide an update when more information on the resumption of operations is available. We know this will be disappointing for passengers and we want to reassure that we are working as hard as possible to resolve the situation.”

More than 83.9 million passengers travelled through the terminals at Heathrow last year and 120 flights to land there where in the air when this closure was announced.

Online tracking services showed flights being diverted to Gatwick, south of London, Charles de Gaulle Airport in Paris and Shannon Airport in Co Clare, Ireland.

A number of flights were also forced to turn around and return to Canada and the US.

Gatwick Airport has accepted seven diverted flights from a number of locations such as Singapore, Johannesburg, and Doha.

@BBCLondonNews There’s a huge fire in Hayes - London, looks like North Hyde Electricity sub station pic.twitter.com/PJNpbHjZxu

— Vil (@fire_at_Vill) March 20, 2025

“We are aware of the situation at Heathrow Airport today and we are supporting by accepting diverted flights as required,” an airport spokesperson said. “Flights are operating from London Gatwick as normal today.”

Shannon Airport confirmed it had accepted six diverted flights from Toronto, Atlanta, Bridgetown Barbados, Boston, Orlando and Newark.

The large-scale power outage in Hayes, Hounslow and the surrounding areas has impacted over 16,300 homes according to Scottish and Southern Electricity Networks as the power company's site says authorities aim to restore power by 3pm today.

A National Grid spokesperson said the fire had damaged equipment and they 'working at speed to restore power supplies as quickly as possible'.

London Fire Brigade said 10 fire engines and around 70 firefighters were still on the scene at Nestles Avenue in Hayes just before 6am with part of a transformer at the substation still alight.

Assistant commissioner Pat Goulbourne said: “This is a highly visible and significant incident, and our firefighters are working tirelessly in challenging conditions to bring the fire under control as swiftly as possible.

“The fire has caused a power outage affecting a large number of homes and local businesses, and we are working closely with our partners to minimise disruption.”

Emergency services were called to the scene at 11.23pm last night and the cause of the blaze is yet to be determined.

Goulbourne said firefighters urged people to take safety precautions as crews worked to extinguish the fire with a 200m cordon in place.

“This will be a prolonged incident, with crews remaining on scene throughout the night,” he said. “As we head into the morning, disruption is expected to increase, and we urge people to avoid the area wherever possible.”