Worst Airlines and Airports for Delays

From checking in your carefully weighed bags to navigating security, airports aren’t the most enjoyable places in the world — even when heading off on a dream holiday. In fact, one poll revealed that over half of Americans find air travel more stressful than a visit to the dentist. [1]

But finding out your flight is delayed — or worse, cancelled — might be the biggest dampener on any trip, forcing activities to be missed, plans to be rearranged, and potentially hundreds of extra pounds [2] to be spent on emergency accommodation or alternative transport.

With this in mind, we wondered: of all the world’s airports and airlines, which are the very worst for delaying and cancelling flights? And what are the most common reasons for flight delays? We analysed two days’ worth of flight tracking data in March 2025 for over 500 airports and over 150 airlines around the world to find out.

Key findings:

Baltimore/Washington International Airport is the worst airport in the world for delaying flights (delaying 53.4% of outbound flights per day)
Air India Express delays one in two (52.7%) flights per day — that’s more than any other global airline
Ronald Reagan Washington National Airport is the worst airport in the world for cancelling flights: 11.5% are called off daily
Air China is the world’s worst airline for cancelling flights, calling off 6.22% of its flights per day
Airline issues like unruly passengers and planes arriving late are the biggest causes of flight delays in the U.S. and UK, respectively

The World’s Worst Airports for Flight Delays

We discovered that Baltimore/Washington International Airport ranks as the worst airport in the world for delays, postponing 53.4% of its daily outbound flights. Across all delayed flights each day, the airport clocks up a combined 52 hours of delay time.

Located a stone’s throw from downtown Baltimore, this airport — which saw 27.06 million passengers in 2024 [3] — was affected by a “massive” power outage in early March 2025 that delayed, diverted, or outright cancelled journeys for thousands of passengers. [4]

The Top 10 World’s Worst Airports for Flight Delays
					Delayed
Rank	Airport	Country	Airport code (include in brackets)	Flights everyday	#	%
1	Baltimore	U.S.	BWI	238	127	53.4%
2	Seoul	South Korea	ICN	481	244	50.7%
3	Ho Chi Minh City	Vietnam	SGN	339	143	42.2%
4	Fukuoka	Japan	FUK	255	96	37.6%
5	Amsterdam	The Netherlands	AMS	569	201	35.3%
6	Haikou	China	HAK	298	103	34.6%
7	Kunming	China	KMG	485	164	33.8%
8	Lisbon	Portugal	LIS	243	77	31.7%
9	Hangzhou	China	HGH	417	125	30.0%
10	Tokyo	Japan	HND	639	179	28.0%

The worst European airport in our ranking — Amsterdam Airport Schiphol, which delays just over one in three (35.3%) flights per day — also experienced a major power failure in 2018 that led to check-in systems failing and terminals being evacuated. [5]

Even the busiest airport in Europe [6] has seen power outages devastate operations: in March 2025, Heathrow Airport in London (which delays 11.8% of flights per day) closed entirely after losing power “equal to that of a mid-sized city” following a substation fire. [7]

The World’s Worst Airlines for Flight Delays

Turning our attention to specific airlines, our data reveals that Air India Express delays a higher proportion (52.7%) of its daily flights than any other global airline. That translates to one in two Air India Express flights being delayed every day.

The budget airline — which operates across India, the Middle East, and Southeast Asia — received criticism in April 2025 after technical glitches saw lengthy delays impact one international airport in India. [8] In another incident caused by technical issues, over 150 Air India Express passengers were stuck at Saudi Arabia’s biggest airport for 24 hours. [9]

The Top 10 World’s Worst Airlines for Flight Delays
				Delayed
Rank	Airline	Country	Flights everyday	#	%
1	Air India Express	India	460	242	52.70%
2	Shenzhen Airlines	China	745	298	40.00%
3	China Southern Airlines	China	2079	801	38.50%
4	Air India	India	711	242	34.10%
5	Shandong Airlines	China	635	200	31.50%
6	JetBlue	U.S.	623	164	26.30%
7	KLM	The Netherlands	614	160	26.10%
8	Hainan Airlines	China	805	204	25.30%
9	Air New Zealand	New Zealand	429	104	24.20%
10	Scandinavian Airlines	Sweden	453	109	24.10%

Bigger-name airlines among the worst in the world for delays include KLM — the oldest operating airline in the world [10] — which delays one in four (26.1%) of its flights per day and has in the past seen disruptions to flight schedules due to planes needing to be de-iced. [11]

According to the World Meteorological Organization, winter weather prompts time-consuming management procedures at airports, with planes needing to take off within 15 minutes of being de-iced or risk needing another de-icing procedure due to snow build-up. [12]

The World’s Worst Airports for Flight Cancellations

If there’s anything worse than a delayed flight, it’s a cancelled one. So which of the world’s airports sees the most cancellations? Our analysis reveals that it’s Ronald Reagan Washington National Airport in Washington, D.C., which cancels 11.5% (or around one in ten) flights per day. Delays are also common: each day, the combined flight delay time here totals 101 hours.

One cause of disruption at the airport — home to the busiest runway in the U.S. [13] and frequented by politicians [14] — is new FAA rules that air traffic be halted when President Trump flies in and out of the area, a provision that follows an in-air collision near the airport in January 2025. [15]

The Top 10 World’s Worst Airports for Flight Cancellations
					Cancelled
Rank	Airport	Country	Airport code (in brackets)	Flights everyday	#	%
1	Washington	U.S.	DCA	392	45	11.5%
2	Baltimore	U.S.	BWI	238	26	10.9%
3	Charlotte	U.S.	CLT	734	75	10.2%
4	Sydney	Australia	SYD	356	28	7.9%
5	Melbourne	Australia	MEL	284	21	7.4%
6	Philadelphia	U.S.	PHL	325	9	2.8%
7	Beijing	China	PEK	562	14	2.5%
7	Amsterdam	The Netherlands	AMS	569	14	2.5%
8	San Diego	U.S.	SAN	232	5	2.2%
9	Bogota	Colombia	BOG	450	9	2.0%
10	Toronto	Canada	YYZ	412	8	1.9%

Also high in the ranking is Charlotte Douglas International Airport in Charlotte, North Carolina (cancelling 10.2% of its daily flights), which saw 600 flights affected by severe thunderstorms and tornadoes along America’s East Coast in March 2025. [16]

Outside of the U.S., Sydney Airport in Australia cancels the highest proportion (7.9%) of daily flights. On one particularly bad day in recent months, poor weather combined with a single air traffic controller calling in sick on short notice halted more than 50 flights. [17]

The World’s Worst Airlines for Flight Cancellations

Air China ranks as the very worst airline for cancelling flights, calling off 6.22% per day. You’re particularly likely to have your Air China flight cancelled if flying from Gatwick to Beijing, which one analysis of Civil Aviation Authority (CAA) data revealed is the worst-performing route for cancellations (of routes with more than 100 annual scheduled departures). [18]

The Top 10 World’s Worst Airlines for Flight Cancellations
				Cancelled
Rank	Airport	Country	Flights everyday	#	%
1	Air China	China	1639	102	6.22%
2	American Airlines	U.S.	4721	283	5.99%
3	Shenzhen Airlines	China	745	32	4.30%
4	KLM	The Netherlands	614	24	3.91%
5	Air India Express	India	460	17	3.78%
6	Southwest	U.S.	2347	85	3.62%
7	Spring Airlines	China	534	17	3.18%
8	China Eastern Airlines	China	2558	73	2.85%
9	Air India	India	711	17	2.45%
10	Air New Zealand	New Zealand	429	7	1.63%

American Airlines ranks next, cancelling 5.99% of its flights per day. Perhaps one of the worst mass-cancellation incidents to affect the airline in recent years occurred in November 2021, when extreme weather issues — compounded by staff shortage — saw 2,300 flights called off. [19] In the future, a new airline policy that could see pilots having to search out their own meals before takeoff could potentially lead to more scheduling disruptions. [20]

The Biggest Causes of Flight Delays in the U.S. and UK

Next, we wanted to hone in on the biggest causes of delayed flights in the UK and U.S. The Federal Aviation Administration (FAA) sorts flight delay causes into five categories, [21] and of those, air carrier delays are the most common for U.S. airlines (causing 28,637 delayed flights in one month).

Air carrier delays are within the control of the carrier and include occurrences like aircraft cleaning and damage, waiting for passengers from connecting flights, fueling, slow boarding, removing unruly passengers, and bird strike — an occurrence estimated to cost the U.S. aviation industry some $400 million a year in damages. [22]

What Causes Flight Delays in the U.S.?
AIR CARRIER	CANCELLED	DIVERTED	AIR CARRIER DELAY	EXTREME WEATHER DELAY	NATIONAL AVIATION SYSTEM DELAY	SECURITY DELAY	LATE ARRIVING AIRCRAFT DELAY
TOTAL	2,629	842	28,637	2,449	25,467	185	27,162

Over in the UK, aircraft arriving late caused the highest proportion (40%) of total delay minutes for UK airlines in 2023. When turnaround times for planes can take over an hour [23], it’s easy to see how a late-arriving plane can trigger a ripple effect of delayed flights down the line — an effect known as delay propagation. [24]

Meanwhile, the UK may be known for its temperamental weather, but extreme weather only accounted for 5.2% of total flight delay minutes in 2023. Delays due to bad weather at UK airports can be attributed to air traffic control’s strict safety rules. [25]

What Causes Flight Delays in the UK?
	Air Carrier Delay	Aircraft Arriving Late	National Aviation System Delay	Security Delay	Extreme Weather
2023	36.4	40	18.1	0.2	5.2

Methodology

We began with a seed list of the world’s 100 busiest airports (measured by scheduled departures daily) and the world’s 100 biggest airlines (based on each airline’s daily average number of flights in one week).

We then used FlightAware flight tracking data from 3rd March to 5th March 2025 to calculate each airport’s proportion of outbound flights per day that are delayed and cancelled (enabling us to rank the worst airports for delays and cancellations, respectively), and to rank airlines by the proportion of daily outbound flights they delay and cancel.

Where FlightAware data was missing for Air India Express and Scandinavian Airlines in our analysis, we used yearly average flight data sourced from Flightright to calculate the proportion of flights delayed and cancelled per day.

To find the biggest causes of flight delays in the U.S., we used Office of Aviation Consumer Protection data collected from 15 American airlines on the number of flights delayed per cause of delay in November 2024.

To find the biggest causes of flight delays in the UK, we used Bureau of Transportation Statistics data to chart each delay cause’s proportion of total delay minutes in 2023 for UK airlines.

Finally, we used Bureau of Transportation Statistics data to calculate the combined total flight delay minutes per day at Baltimore/Washington International Airport and Ronald Reagan Washington National Airport.

Sources

[1] Expedia, ‘New Report Finds Air Travel More Stressful Than Going to the Dentist: Expedia Releases 2024 Air Travel Hacks Report for Smoother Travel’

[2] AirHelp, ‘What’s the true cost of a flight delay?’

[3] FFXNow, ‘Dulles Airport’s 2024 passenger total set new all-time record’

[4] Fox Business, ‘Massive power outage at BWI airport impacts thousands of passengers with extensive delays’

[5] Euro News, ‘Power failure closes Amsterdam’s Schiphol Airport’

[6] OAG, ‘Top 10: Europe’s Busiest Airports in 2024’

[7] BBC, ‘Heathrow flights resume after fire forced shutdown’

[8] Times of India, ‘Frequent snags in Air India Express flights irk flyers’

[9] Times of India, ‘Bengaluru-bound passengers stranded for over 18 hours as Air India Express flight faces repeated tech failures in Saudi Arabia’

[10] CNN Travel, ‘10 oldest airlines in the world’

[11] Euro News, ‘Schiphol Airport and KLM warn more than a hundred flights disrupted due to ‘de-icing’ issues’

[12] World Meteorological Organization, ‘Aviation | Hazards | Winter Weather’

[13] Axios, ‘Why Reagan National Airport has the country’s busiest runway’

[14] Washington, D.C., ‘Everything you need to know about the airports closest to Washington, DC including transportation information, airport maps and much more.’

[15] Fox 5 DC, ‘New FAA rules at DCA halt air traffic for president’s Marine One travel’

[16] Yahoo, ‘Severe weather disrupts more than 600 flights at Charlotte Douglas International Airport’

[17] New.com.au, ‘Hundreds stranded as flights cancelled at Sydney Airport’

[18] The Telegraph, ‘Revealed: The best (and worst) airlines and airports for delays and cancellations’

[19] Reuters, ‘American Airlines cancels more flights; total tops 2,300’

[20] Aviation A2Z, ‘American Airlines Pilots Can Delay Your Flights Due to this Reason’

[21] Federal Aviation Administration, ‘Types of Delay’

[22] Navjot S. Sodhi, Competition in the Air: Birds Versus Aircraft, The Auk, Volume 119, Issue 3, 1 July 2002, Pages 587–595, https://doi.org/10.1093/auk/119.3.587

[23] The Telegraph, ‘How long does it take to turn a plane around – and what’s the fastest way to board?’

[24] Federal Aviation Administration, ‘Delay Propagation’

[25] BBC, ‘Why does Britain face flight chaos during bad weather?’