St Louis Lambert International in September 2024

86.3%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 2024, reporting carriers scheduled 5,496 domestic departures from St Louis Lambert International (STL). 86.3% left less than 15 minutes late and 87.3% reached their destination on time; 0.5% were cancelled.

Nationally that month, 84.4% of flights departed on time and 83.9% arrived on time, so STL departures were 1.9 points above the national departure figure.

A year earlier, in September 2023, the airport had 5,346 departures with 80.4% leaving on time: a change of +5.9 points, with flights up 3%.

Flights arriving at STL that month were on time 87.3% of the time (5,497 scheduled arrivals).

Of the delay minutes that carriers assigned to a BTS cause category that month, late-arriving aircraft 41%, air carrier 37% and national aviation system 20%.

On time 87.3%
Arrived 15+ minutes late 12.2%
Cancelled 0.5%
Diverted 0.0%

Every scheduled departure from STL in September 2024, judged by arrival at the destination.

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

Measure	Sep 2024	Sep 2023	STL, 12 months to Jul 2026	All reported flights, Sep 2024
Departed on time	86.3%	80.4%	74.1%	84.4%
Arrived on time	87.3%	80.2%	76.8%	83.9%
Cancelled	0.5%	0.8%	1.3%	0.6%
Average departure delay (late minutes only)	8.1 min	13.0 min	17.6 min	10.6 min
Scheduled departures a day	183	178	174	19,421
Scheduled departures	5,496	5,346	63,318	582,622

Airlines that month

Reporting carrier	Flights	Share	On time	Avg arrival delay	Cancelled
WN Southwest Airlines	3,428	62%	87.5%	-1.9 min	0.5%
AA American Airlines	640	12%	85.3%	4.6 min	0.9%
DL Delta Air Lines	485	9%	91.1%	-5.8 min	0.0%
UA United Airlines	278	5%	82.7%	4.3 min	0.7%
MQ Envoy Air	165	3%	80.6%	2.2 min	0.0%
YX Republic Airline	123	2%	93.5%	-9.6 min	0.0%
9E Endeavor Air	113	2%	98.2%	-17.1 min	0.0%
AS Alaska Airlines	78	1%	92.3%	-9.4 min	0.0%
F9 Frontier Airlines	78	1%	70.5%	8.5 min	2.6%
OO SkyWest Airlines	47	1%	83.0%	-4.4 min	0.0%
NK Spirit Airlines	35	1%	85.7%	2.4 min	0.0%
OH PSA Airlines	26	0%	88.5%	-7.4 min	0.0%

Busiest routes that month

Route	Cities	Flights	On time	Avg arrival delay	Cancelled
STL–DEN	St. Louis to Denver	307	87.0%	-2.0 min	0.3%
STL–LGA	St. Louis to New York	300	95.3%	-10.9 min	0.0%
STL–ATL	St. Louis to Atlanta	285	87.4%	-3.7 min	0.4%
STL–ORD	St. Louis to Chicago	221	79.6%	11.3 min	0.5%
STL–DFW	St. Louis to Dallas/Fort Worth	213	84.5%	0.3 min	0.0%
STL–DCA	St. Louis to Washington	189	92.6%	-6.4 min	0.0%
STL–CLT	St. Louis to Charlotte	179	82.7%	4.0 min	2.8%
STL–PHX	St. Louis to Phoenix	176	87.5%	-2.7 min	0.6%
STL–MCO	St. Louis to Orlando	174	93.1%	-6.8 min	0.6%
STL–PHL	St. Louis to Philadelphia	172	88.4%	6.4 min	0.0%
STL–DAL	St. Louis to Dallas	170	85.3%	-0.9 min	1.2%
STL–MSP	St. Louis to Minneapolis	166	89.8%	-11.5 min	0.0%

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 2024.

Delay causes

BTS cause category	Share of delay minutes	National, Sep 2024	Minutes
Air carrier	36.8%	38.6%	13,261
Late-arriving aircraft	41.4%	38.4%	14,921
National Aviation System	19.6%	18.2%	7,053
Extreme weather	2.1%	4.8%	753
Security	0.0%	0.1%	17

36,005 delay minutes on 672 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 September 2024?

86.3% of 5,496 scheduled domestic departures left less than 15 minutes late, and 87.3% reached their destination on time. The national figures that month were 84.4% and 83.9%.

How does that compare with a year earlier?

In September 2023, 80.4% of 5,346 departures left on time and 0.8% were cancelled, against 86.3% and 0.5% in September 2024.

Provenance

Source: Bureau of Transportation Statistics, Reporting Carrier On-Time Performance, file for September 2024; 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.