Washington Dulles International in April 2026

89.0%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 April 2026, reporting carriers scheduled 4,843 domestic departures from Washington Dulles International (IAD). 89.0% left less than 15 minutes late and 86.8% reached their destination on time; 0.3% were cancelled.

Nationally that month, 79.1% of flights departed on time and 78.9% arrived on time, so IAD departures were 9.9 points above the national departure figure.

A year earlier, in April 2025, the airport had 5,036 departures with 87.0% leaving on time: a change of +2.0 points, with flights down 4%.

Flights arriving at IAD that month were on time 88.5% of the time (4,779 scheduled arrivals).

Of the delay minutes that carriers assigned to a BTS cause category that month, air carrier 38%, late-arriving aircraft 31% and national aviation system 30%.

On time 86.8%
Arrived 15+ minutes late 12.7%
Cancelled 0.3%
Diverted 0.2%

Every scheduled departure from IAD in April 2026, judged by arrival at the destination.

April 2026 against a year earlier, the airport's year and the nation

Measure	Apr 2026	Apr 2025	IAD, 12 months to Jul 2026	All reported flights, Apr 2026
Departed on time	89.0%	87.0%	82.6%	79.1%
Arrived on time	86.8%	82.3%	80.1%	78.9%
Cancelled	0.3%	0.4%	1.4%	0.9%
Average departure delay (late minutes only)	9.5 min	10.1 min	14.7 min	14.5 min
Scheduled departures a day	161	168	159	19,931
Scheduled departures	4,843	5,036	58,031	597,919

Airlines that month

Reporting carrier	Flights	Share	On time	Avg arrival delay	Cancelled
UA United Airlines	3,336	69%	88.0%	-3.7 min	0.1%
YX Republic Airline	437	9%	89.7%	-4.9 min	0.0%
DL Delta Air Lines	270	6%	88.5%	-6.9 min	1.9%
OO SkyWest Airlines	243	5%	84.4%	8.2 min	1.2%
AA American Airlines	134	3%	73.9%	12.5 min	0.7%
F9 Frontier Airlines	126	3%	72.2%	2.9 min	2.4%
AS Alaska Airlines	96	2%	79.2%	2.0 min	0.0%
WN Southwest Airlines	90	2%	72.2%	13.0 min	0.0%
OH PSA Airlines	69	1%	89.9%	8.2 min	1.4%
G4 Allegiant Air	42	1%	85.7%	-4.7 min	0.0%

Busiest routes that month

Route	Cities	Flights	On time	Avg arrival delay	Cancelled
IAD–ATL	Washington to Atlanta	354	86.4%	-5.6 min	1.1%
IAD–DEN	Washington to Denver	291	87.3%	-2.1 min	0.0%
IAD–SFO	Washington to San Francisco	229	80.8%	4.3 min	0.0%
IAD–LAX	Washington to Los Angeles	224	79.5%	-0.5 min	0.4%
IAD–MCO	Washington to Orlando	212	90.6%	-10.5 min	0.5%
IAD–ORD	Washington to Chicago	181	75.7%	17.1 min	0.0%
IAD–CLT	Washington to Charlotte	173	90.8%	-1.4 min	0.6%
IAD–DFW	Washington to Dallas/Fort Worth	152	75.0%	11.7 min	0.7%
IAD–IAH	Washington to Houston	146	88.4%	-6.5 min	0.0%
IAD–SEA	Washington to Seattle	128	82.0%	-0.7 min	0.8%
IAD–BOS	Washington to Boston	120	80.8%	-0.2 min	0.0%
IAD–EWR	Washington to Newark	120	89.2%	-1.6 min	0.0%

By scheduled departure hour

100

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

Share of departures that left less than 15 minutes late, by scheduled hour (local time), April 2026.

Delay causes

BTS cause category	Share of delay minutes	National, Apr 2026	Minutes
Air carrier	37.7%	33.5%	16,377
Late-arriving aircraft	30.5%	40.4%	13,253
National Aviation System	29.5%	21.0%	12,823
Extreme weather	2.2%	5.0%	976
Security	0.1%	0.1%	41

43,470 delay minutes on 617 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 April 2026?

89.0% of 4,843 scheduled domestic departures left less than 15 minutes late, and 86.8% reached their destination on time. The national figures that month were 79.1% and 78.9%.

How does that compare with a year earlier?

In April 2025, 87.0% of 5,036 departures left on time and 0.4% were cancelled, against 89.0% and 0.3% in April 2026.

Provenance

Source: Bureau of Transportation Statistics, Reporting Carrier On-Time Performance, file for April 2026; 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.