Baltimore/Washington International Thurgood Marshall in September 2025

82.2%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 September 2025, reporting carriers scheduled 7,968 domestic departures from Baltimore/Washington International Thurgood Marshall (BWI). 82.2% left less than 15 minutes late and 85.2% reached their destination on time; 0.2% were cancelled.

Nationally that month, 83.1% of flights departed on time and 82.8% arrived on time, so BWI departures were 0.9 points below the national departure figure.

A year earlier, in September 2024, the airport had 8,273 departures with 79.9% leaving on time: a change of +2.3 points, with flights down 4%.

Flights arriving at BWI that month were on time 86.2% of the time (7,965 scheduled arrivals).

Of the delay minutes that carriers assigned to a BTS cause category that month, late-arriving aircraft 37%, air carrier 32% and national aviation system 26%.

On time 85.2%
Arrived 15+ minutes late 14.5%
Cancelled 0.2%
Diverted 0.2%

Every scheduled departure from BWI in September 2025, judged by arrival at the destination.

September 2025 against a year earlier, the airport's year and the nation

Measure	Sep 2025	Sep 2024	BWI, 12 months to Jul 2026	All reported flights, Sep 2025
Departed on time	82.2%	79.9%	71.7%	83.1%
Arrived on time	85.2%	82.8%	76.4%	82.8%
Cancelled	0.2%	0.6%	1.8%	0.5%
Average departure delay (late minutes only)	10.4 min	10.6 min	16.5 min	12.2 min
Scheduled departures a day	266	276	259	18,748
Scheduled departures	7,968	8,273	94,429	562,439

Airlines that month

Reporting carrier	Flights	Share	On time	Avg arrival delay	Cancelled
WN Southwest Airlines	5,998	75%	85.2%	0.5 min	0.1%
DL Delta Air Lines	453	6%	92.1%	-6.4 min	0.0%
NK Spirit Airlines	429	5%	86.7%	-4.6 min	1.2%
UA United Airlines	363	5%	85.7%	-2.1 min	0.0%
AA American Airlines	257	3%	88.3%	-4.0 min	0.8%
F9 Frontier Airlines	219	3%	77.2%	3.5 min	0.5%
YX Republic Airline	100	1%	63.0%	15.9 min	3.0%
MQ Envoy Air	87	1%	77.0%	-0.5 min	0.0%
AS Alaska Airlines	60	1%	85.0%	-2.4 min	0.0%
OH PSA Airlines	1	0%	100.0%	-15.0 min	0.0%
OO SkyWest Airlines	1	0%	0.0%	28.0 min	0.0%

Busiest routes that month

Route	Cities	Flights	On time	Avg arrival delay	Cancelled
BWI–ATL	Baltimore to Atlanta	465	88.2%	-3.5 min	0.0%
BWI–MCO	Baltimore to Orlando	342	86.3%	-1.4 min	0.6%
BWI–BOS	Baltimore to Boston	288	59.4%	26.8 min	1.4%
BWI–DEN	Baltimore to Denver	266	83.8%	-0.1 min	0.0%
BWI–CLT	Baltimore to Charlotte	252	88.5%	-2.8 min	0.4%
BWI–ORD	Baltimore to Chicago	248	81.9%	0.2 min	0.0%
BWI–FLL	Baltimore to Fort Lauderdale	236	83.1%	1.7 min	0.8%
BWI–DTW	Baltimore to Detroit	218	86.7%	-4.7 min	0.9%
BWI–TPA	Baltimore to Tampa	200	89.5%	-2.4 min	0.0%
BWI–MDW	Baltimore to Chicago	181	85.6%	-1.6 min	0.6%
BWI–PVD	Baltimore to Providence	172	86.0%	-0.8 min	0.0%
BWI–LAX	Baltimore to Los Angeles	169	80.5%	1.0 min	0.6%

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), September 2025.

Delay causes

BTS cause category	Share of delay minutes	National, Sep 2025	Minutes
Air carrier	31.9%	34.3%	20,502
Late-arriving aircraft	37.0%	37.4%	23,778
National Aviation System	25.8%	22.6%	16,598
Extreme weather	5.2%	5.6%	3,351
Security	0.1%	0.1%	82

64,311 delay minutes on 1,154 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 BWI on time in September 2025?

82.2% of 7,968 scheduled domestic departures left less than 15 minutes late, and 85.2% reached their destination on time. The national figures that month were 83.1% and 82.8%.

How does that compare with a year earlier?

In September 2024, 79.9% of 8,273 departures left on time and 0.6% were cancelled, against 82.2% and 0.2% in September 2025.

Provenance

Source: Bureau of Transportation Statistics, Reporting Carrier On-Time Performance, file for September 2025; public domain. Domestic scheduled flights by reporting carriers, totals and averages only. The site's data runs through July 2026. Full record for BWI · methodology · corrections.