St Louis Lambert International in March 2025

79.9%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 March 2025, reporting carriers scheduled 5,379 domestic departures from St Louis Lambert International (STL). 79.9% left less than 15 minutes late and 81.1% reached their destination on time; 0.9% were cancelled.

Nationally that month, 79.9% of flights departed on time and 79.3% arrived on time, so STL departures were level with the national departure figure.

A year earlier, in March 2024, the airport had 5,451 departures with 77.1% leaving on time: a change of +2.8 points, with flights down 1%.

Flights arriving at STL that month were on time 81.9% of the time (5,376 scheduled arrivals).

Of the delay minutes that carriers assigned to a BTS cause category that month, late-arriving aircraft 43%, air carrier 30% and national aviation system 23%.

On time 81.1%
Arrived 15+ minutes late 17.7%
Cancelled 0.9%
Diverted 0.3%

Every scheduled departure from STL in March 2025, judged by arrival at the destination.

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

Measure	Mar 2025	Mar 2024	STL, 12 months to Jul 2026	All reported flights, Mar 2025
Departed on time	79.9%	77.1%	74.1%	79.9%
Arrived on time	81.1%	79.1%	76.8%	79.3%
Cancelled	0.9%	0.8%	1.3%	1.2%
Average departure delay (late minutes only)	14.2 min	15.0 min	17.6 min	14.9 min
Scheduled departures a day	179	182	174	20,029
Scheduled departures	5,379	5,451	63,318	600,872

Airlines that month

Reporting carrier	Flights	Share	On time	Avg arrival delay	Cancelled
WN Southwest Airlines	3,547	66%	81.3%	3.1 min	0.6%
DL Delta Air Lines	431	8%	89.8%	-8.2 min	0.2%
AA American Airlines	420	8%	81.9%	13.2 min	1.4%
YX Republic Airline	309	6%	83.5%	0.7 min	1.6%
UA United Airlines	203	4%	73.9%	10.5 min	0.0%
MQ Envoy Air	125	2%	68.0%	15.0 min	4.0%
OH PSA Airlines	112	2%	70.5%	11.8 min	7.1%
OO SkyWest Airlines	88	2%	79.5%	13.5 min	0.0%
F9 Frontier Airlines	78	1%	65.4%	9.1 min	1.3%
AS Alaska Airlines	52	1%	84.6%	2.2 min	0.0%
NK Spirit Airlines	14	0%	64.3%	5.4 min	7.1%

Busiest routes that month

Route	Cities	Flights	On time	Avg arrival delay	Cancelled
STL–DEN	St. Louis to Denver	293	79.9%	2.3 min	0.0%
STL–ATL	St. Louis to Atlanta	282	85.8%	-4.3 min	0.0%
STL–ORD	St. Louis to Chicago	228	75.4%	8.1 min	2.2%
STL–MCO	St. Louis to Orlando	226	77.9%	2.1 min	0.9%
STL–LGA	St. Louis to New York	218	81.2%	2.6 min	0.9%
STL–DFW	St. Louis to Dallas/Fort Worth	183	78.7%	18.7 min	4.4%
STL–CLT	St. Louis to Charlotte	182	81.3%	12.0 min	0.0%
STL–PHX	St. Louis to Phoenix	181	79.6%	12.0 min	0.0%
STL–DCA	St. Louis to Washington	175	65.7%	15.4 min	4.0%
STL–DAL	St. Louis to Dallas	173	85.5%	1.6 min	1.7%
STL–LAS	St. Louis to Las Vegas	173	82.1%	-2.3 min	1.2%
STL–MSP	St. Louis to Minneapolis	170	87.6%	-3.0 min	0.6%

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), March 2025.

Delay causes

BTS cause category	Share of delay minutes	National, Mar 2025	Minutes
Air carrier	30.0%	33.0%	20,368
Late-arriving aircraft	42.9%	39.2%	29,147
National Aviation System	23.0%	21.9%	15,628
Extreme weather	4.2%	5.9%	2,840
Security	0.0%	0.1%	18

68,001 delay minutes on 953 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 STL on time in March 2025?

79.9% of 5,379 scheduled domestic departures left less than 15 minutes late, and 81.1% reached their destination on time. The national figures that month were 79.9% and 79.3%.

How does that compare with a year earlier?

In March 2024, 77.1% of 5,451 departures left on time and 0.8% were cancelled, against 79.9% and 0.9% in March 2025.

Provenance

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