St Louis Lambert International in December 2024

77.3%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 December 2024, reporting carriers scheduled 5,384 domestic departures from St Louis Lambert International (STL). 77.3% left less than 15 minutes late and 80.7% reached their destination on time; 0.4% were cancelled.

Nationally that month, 77.8% of flights departed on time and 78.1% arrived on time, so STL departures were 0.5 points below the national departure figure.

A year earlier, in December 2023, the airport had 5,270 departures with 79.9% leaving on time: a change of −2.6 points, with flights up 2%.

Flights arriving at STL that month were on time 81.4% of the time (5,384 scheduled arrivals).

Of the delay minutes that carriers assigned to a BTS cause category that month, late-arriving aircraft 42%, air carrier 36% and national aviation system 20%.

On time 80.7%
Arrived 15+ minutes late 18.7%
Cancelled 0.4%
Diverted 0.1%

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

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

Measure	Dec 2024	Dec 2023	STL, 12 months to Jul 2026	All reported flights, Dec 2024
Departed on time	77.3%	79.9%	74.1%	77.8%
Arrived on time	80.7%	81.8%	76.8%	78.1%
Cancelled	0.4%	0.4%	1.3%	0.7%
Average departure delay (late minutes only)	14.7 min	11.5 min	17.6 min	16.6 min
Scheduled departures a day	180	176	174	19,686
Scheduled departures	5,384	5,270	63,318	590,581

Airlines that month

Reporting carrier	Flights	Share	On time	Avg arrival delay	Cancelled
WN Southwest Airlines	3,466	64%	81.0%	2.7 min	0.3%
AA American Airlines	498	9%	76.5%	14.3 min	1.2%
DL Delta Air Lines	429	8%	87.2%	-1.2 min	0.0%
YX Republic Airline	289	5%	87.5%	-2.6 min	0.0%
UA United Airlines	235	4%	77.4%	9.8 min	0.4%
9E Endeavor Air	104	2%	85.6%	-3.6 min	1.0%
MQ Envoy Air	91	2%	62.6%	18.6 min	2.2%
F9 Frontier Airlines	86	2%	79.1%	3.6 min	1.2%
OO SkyWest Airlines	63	1%	71.4%	34.2 min	0.0%
AS Alaska Airlines	54	1%	85.2%	-5.7 min	0.0%
OH PSA Airlines	51	1%	62.7%	30.1 min	0.0%
NK Spirit Airlines	18	0%	72.2%	15.6 min	0.0%

Busiest routes that month

Route	Cities	Flights	On time	Avg arrival delay	Cancelled
STL–DEN	St. Louis to Denver	308	84.7%	-0.4 min	0.3%
STL–LGA	St. Louis to New York	308	83.4%	0.9 min	0.3%
STL–ATL	St. Louis to Atlanta	292	82.2%	1.2 min	0.0%
STL–PHX	St. Louis to Phoenix	215	82.3%	1.8 min	0.0%
STL–DFW	St. Louis to Dallas/Fort Worth	202	65.8%	24.3 min	3.5%
STL–MCO	St. Louis to Orlando	201	80.1%	4.1 min	0.5%
STL–DAL	St. Louis to Dallas	183	72.7%	11.5 min	0.5%
STL–DCA	St. Louis to Washington	177	82.5%	7.9 min	0.6%
STL–CLT	St. Louis to Charlotte	176	80.1%	16.3 min	0.0%
STL–ORD	St. Louis to Chicago	175	80.0%	7.6 min	0.6%
STL–LAS	St. Louis to Las Vegas	173	80.9%	-1.7 min	0.0%
STL–MSP	St. Louis to Minneapolis	172	77.3%	12.6 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), December 2024.

Delay causes

BTS cause category	Share of delay minutes	National, Dec 2024	Minutes
Air carrier	36.3%	34.3%	23,248
Late-arriving aircraft	41.9%	40.2%	26,793
National Aviation System	20.1%	17.8%	12,847
Extreme weather	1.4%	7.5%	876
Security	0.4%	0.2%	229

63,993 delay minutes on 1,009 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 December 2024?

77.3% of 5,384 scheduled domestic departures left less than 15 minutes late, and 80.7% reached their destination on time. The national figures that month were 77.8% and 78.1%.

How does that compare with a year earlier?

In December 2023, 79.9% of 5,270 departures left on time and 0.4% were cancelled, against 77.3% and 0.4% in December 2024.

Provenance

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