By Duarte Dias,
March 21, 2025 / 12:05 PM EDT / CBS News
London — The sudden, full-day closure of London’s Heathrow Airport on Friday caused by a fire in a nearby electrical substation threw the travel plans of an estimated 200,000 people into disarray. Heathrow is one of the world’s busiest, most internationally connected airports, and it warned in a statement Friday that it expected “significant disruption over the coming days,” telling passengers not to go to the airport “under any circumstances” until it reopens.
According to the FlightRadar24 tracking website, an estimated 1,350 flights were directly impacted by the Heathrow closure on Friday. The effects of the shutdown are expected to linger for days as so much international travel relies on the facility as a hub for connections.
Below is a look at the busiest airports in the world this month, according to statistics compiled by the global travel data platform OAG.
What is the busiest airport in the world?
The busiest airport in the world in March 2025, as measured by the number of seats available on both domestic and international flights, is Atlanta Hartsfield-Jackson, with a capacity of nearly 5.4 million seats. It is also easily the busiest airport in the United States.
Atlanta is followed closely in the OAG rankings by Dubai International and then Haneda Airport outside Japan’s capital of Tokyo.
In March, Dallas Fort Worth International is ranked at No. 4, with just over 4.1 million airline seats available on its routes.
Heathrow comes in at No. 5 on the list of the world’s busiest airports this month. The OAG statistics show Heathrow and Dallas Fort Worth swapped positions in the ranking between March 2024 and this month.
Overall during 2024, the top five looked the same in OAG’s rankings as this month, but Heathrow held onto the 4th-busiest slot for the year, edging out Dallas Fort Worth with a total of 51.55 million seats available compared to the Texas hub’s 51.51 million.
Below is the list of the airports that round out OAG’s ranking of the top 10 busiest in the world in March 2025:
6. Shanghai Pudong International Airport in China
7. Denver International Airport in Colorado
8. Delhi Airport in India
9. Chicago O’Hare International in Illinois
10. Baiyun International in China
While it is not the busiest by measure of the number of seats available on scheduled flights, London’s Heathrow is the best-connected airport in the world, according to OAG, as measured by the total number of destinations served and the number of scheduled connections.
If domestic flights are removed from the equation, Heathrow would move up the ranking to become the world’s second busiest airport, behind only Dubai International.
Heathrow is also the busiest of Europe’s airports, by number of seats available.
Which airport has the largest footprint?
While it doesn’t even make the list of the top 10 busiest facilities on the planet, Saudi Arabia’s King Fahd International Airport holds a record of its own — officially.
According to Guinness World Records, King Fahd, which is near the city of Dammam, about 200 miles east of the Saudi capital Riyadh, is the world’s largest airport.
It sprawls over a remarkable 300 square miles, according to the Guinness World Records website. Heathrow, by comparison, covers just under five square miles on its plot about 14 miles west of central London.
