Washington Dulles International in July 2024

74.4%departed on time

BTS: A flight is counted as on time if it arrived less than 15 minutes after its scheduled time. Only carriers with at least 0.5 percent of domestic scheduled passenger revenue report.

In July 2024, reporting carriers scheduled 4,692 domestic departures from Washington Dulles International (IAD). 74.4% left less than 15 minutes late and 73.0% reached their destination on time; 2.2% were cancelled.

Nationally that month, 68.5% of flights departed on time and 68.1% arrived on time, so IAD departures were 5.9 points above the national departure figure.

Flights arriving at IAD that month were on time 75.0% of the time (4,692 scheduled arrivals).

Of the delay minutes that carriers assigned to a BTS cause category that month, air carrier 40%, late-arriving aircraft 32% and national aviation system 20%.

On time 73.0%
Arrived 15+ minutes late 24.5%
Cancelled 2.2%
Diverted 0.3%

Every scheduled departure from IAD in July 2024, judged by arrival at the destination.

July 2024 against a year earlier, the airport's year and the nation

Measure	Jul 2024	Year earlier	IAD, 12 months to Jul 2026	All reported flights, Jul 2024
Departed on time	74.4%	—	82.6%	68.5%
Arrived on time	73.0%	—	80.1%	68.1%
Cancelled	2.2%	—	1.4%	2.9%
Average departure delay (late minutes only)	20.8 min	—	14.7 min	24.9 min
Scheduled departures a day	156	—	159	21,154
Scheduled departures	4,692	—	58,031	634,613

Airlines that month

Reporting carrier	Flights	Share	On time	Avg arrival delay	Cancelled
UA United Airlines	2,691	57%	72.3%	13.2 min	2.2%
YX Republic Airline	803	17%	78.3%	4.9 min	2.2%
DL Delta Air Lines	301	6%	65.8%	25.2 min	6.0%
OO SkyWest Airlines	281	6%	71.5%	27.5 min	0.4%
AS Alaska Airlines	248	5%	77.0%	7.7 min	0.0%
OH PSA Airlines	150	3%	71.3%	15.4 min	3.3%
WN Southwest Airlines	116	2%	71.6%	10.1 min	0.0%
AA American Airlines	61	1%	78.7%	3.9 min	1.6%
G4 Allegiant Air	41	1%	53.7%	20.6 min	2.4%

Busiest routes that month

Route	Cities	Flights	On time	Avg arrival delay	Cancelled
IAD–DEN	Washington to Denver	303	77.9%	8.4 min	0.3%
IAD–ATL	Washington to Atlanta	294	66.0%	24.3 min	5.4%
IAD–SEA	Washington to Seattle	278	79.5%	3.7 min	1.8%
IAD–LAX	Washington to Los Angeles	248	80.6%	2.4 min	1.2%
IAD–SFO	Washington to San Francisco	248	76.2%	4.6 min	0.8%
IAD–CLT	Washington to Charlotte	182	72.0%	15.1 min	3.3%
IAD–IAH	Washington to Houston	155	59.4%	26.5 min	5.2%
IAD–ORD	Washington to Chicago	154	70.8%	5.2 min	3.2%
IAD–DFW	Washington to Dallas/Fort Worth	144	80.6%	11.0 min	1.4%
IAD–BOS	Washington to Boston	124	70.2%	24.8 min	0.8%
IAD–LGA	Washington to New York	124	62.1%	10.3 min	5.6%
IAD–MCO	Washington to Orlando	124	63.7%	17.7 min	2.4%

By scheduled departure hour

On-time share:under 62%6270768288% and over

Share of departures that left less than 15 minutes late, by scheduled hour (local time), July 2024.

Delay causes

BTS cause category	Share of delay minutes	National, Jul 2024	Minutes
Air carrier	39.8%	36.6%	36,421
Late-arriving aircraft	32.4%	42.7%	29,576
National Aviation System	20.4%	16.0%	18,618
Extreme weather	7.4%	4.6%	6,738
Security	0.1%	0.1%	62

91,415 delay minutes on 1,151 flights that arrived 15 or more minutes late and carried a cause report. Carriers assign the categories; see what each category means.

Questions and answers

How many flights left IAD on time in July 2024?

74.4% of 4,692 scheduled domestic departures left less than 15 minutes late, and 73.0% reached their destination on time. The national figures that month were 68.5% and 68.1%.

How does that compare with a year earlier?

July 2023 is outside the 36 months on file, or the airport had too few reported flights that month.

Provenance

Source: Bureau of Transportation Statistics, Reporting Carrier On-Time Performance, file for July 2024; public domain. Domestic scheduled flights by reporting carriers, totals and averages only. The site's data runs through July 2026. Full record for IAD · methodology · corrections.