St Louis Lambert International in June 2025

71.6%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 June 2025, reporting carriers scheduled 5,733 domestic departures from St Louis Lambert International (STL). 71.6% left less than 15 minutes late and 71.8% reached their destination on time; 1.0% were cancelled.

Nationally that month, 71.4% of flights departed on time and 70.3% arrived on time, so STL departures were level with the national departure figure.

A year earlier, in June 2024, the airport had 5,825 departures with 73.7% leaving on time: a change of −2.1 points, with flights down 2%.

Flights arriving at STL that month were on time 72.6% of the time (5,732 scheduled arrivals).

Of the delay minutes that carriers assigned to a BTS cause category that month, late-arriving aircraft 50%, air carrier 27% and national aviation system 19%.

On time 71.8%
Arrived 15+ minutes late 26.6%
Cancelled 1.0%
Diverted 0.6%

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

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

Measure	Jun 2025	Jun 2024	STL, 12 months to Jul 2026	All reported flights, Jun 2025
Departed on time	71.6%	73.7%	74.1%	71.4%
Arrived on time	71.8%	75.6%	76.8%	70.3%
Cancelled	1.0%	0.7%	1.3%	1.6%
Average departure delay (late minutes only)	21.1 min	16.8 min	17.6 min	22.1 min
Scheduled departures a day	191	194	174	20,386
Scheduled departures	5,733	5,825	63,318	611,575

Airlines that month

Reporting carrier	Flights	Share	On time	Avg arrival delay	Cancelled
WN Southwest Airlines	3,673	64%	71.8%	12.7 min	0.3%
AA American Airlines	511	9%	71.4%	25.8 min	2.2%
DL Delta Air Lines	489	9%	83.6%	0.4 min	1.6%
UA United Airlines	273	5%	62.6%	29.5 min	0.0%
OO SkyWest Airlines	208	4%	67.3%	21.9 min	1.0%
YX Republic Airline	184	3%	68.5%	11.0 min	8.7%
MQ Envoy Air	154	3%	74.7%	16.0 min	0.6%
AS Alaska Airlines	90	2%	62.2%	21.8 min	1.1%
F9 Frontier Airlines	80	1%	56.3%	19.2 min	0.0%
OH PSA Airlines	49	1%	73.5%	17.9 min	10.2%
NK Spirit Airlines	22	0%	77.3%	-5.3 min	9.1%

Busiest routes that month

Route	Cities	Flights	On time	Avg arrival delay	Cancelled
STL–DEN	St. Louis to Denver	339	65.5%	23.5 min	0.0%
STL–ATL	St. Louis to Atlanta	331	78.5%	6.4 min	1.5%
STL–ORD	St. Louis to Chicago	294	70.1%	20.7 min	1.0%
STL–LGA	St. Louis to New York	219	66.2%	15.6 min	5.5%
STL–DFW	St. Louis to Dallas/Fort Worth	218	61.0%	31.3 min	2.8%
STL–MCO	St. Louis to Orlando	201	71.6%	11.9 min	0.0%
STL–DCA	St. Louis to Washington	194	60.8%	31.4 min	2.6%
STL–DTW	St. Louis to Detroit	176	79.5%	6.6 min	1.1%
STL–CLT	St. Louis to Charlotte	169	72.2%	22.9 min	1.2%
STL–PHX	St. Louis to Phoenix	169	72.2%	19.9 min	0.0%
STL–LAS	St. Louis to Las Vegas	167	73.1%	8.3 min	0.6%
STL–MDW	St. Louis to Chicago	163	78.5%	6.6 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), June 2025.

Delay causes

BTS cause category	Share of delay minutes	National, Jun 2025	Minutes
Air carrier	27.4%	31.6%	29,510
Late-arriving aircraft	50.0%	40.6%	53,785
National Aviation System	18.5%	20.9%	19,869
Extreme weather	4.0%	6.9%	4,346
Security	0.1%	0.2%	132

107,642 delay minutes on 1,524 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 June 2025?

71.6% of 5,733 scheduled domestic departures left less than 15 minutes late, and 71.8% reached their destination on time. The national figures that month were 71.4% and 70.3%.

How does that compare with a year earlier?

In June 2024, 73.7% of 5,825 departures left on time and 0.7% were cancelled, against 71.6% and 1.0% in June 2025.

Provenance

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