St Louis Lambert International in July 2025

68.4%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 July 2025, reporting carriers scheduled 5,855 domestic departures from St Louis Lambert International (STL). 68.4% left less than 15 minutes late and 70.2% reached their destination on time; 1.6% were cancelled.

Nationally that month, 69.7% of flights departed on time and 69.0% arrived on time, so STL departures were 1.3 points below the national departure figure.

A year earlier, in July 2024, the airport had 6,029 departures with 65.3% leaving on time: a change of +3.1 points, with flights down 3%.

Flights arriving at STL that month were on time 72.0% of the time (5,856 scheduled arrivals).

Of the delay minutes that carriers assigned to a BTS cause category that month, late-arriving aircraft 46%, air carrier 31% and national aviation system 20%.

On time 70.2%
Arrived 15+ minutes late 27.8%
Cancelled 1.6%
Diverted 0.4%

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

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

Measure	Jul 2025	Jul 2024	STL, 12 months to Jul 2026	All reported flights, Jul 2025
Departed on time	68.4%	65.3%	74.1%	69.7%
Arrived on time	70.2%	68.0%	76.8%	69.0%
Cancelled	1.6%	1.9%	1.3%	2.5%
Average departure delay (late minutes only)	22.9 min	24.7 min	17.6 min	24.3 min
Scheduled departures a day	195	201	174	21,048
Scheduled departures	5,855	6,029	63,318	631,428

Airlines that month

Reporting carrier	Flights	Share	On time	Avg arrival delay	Cancelled
WN Southwest Airlines	3,750	64%	70.4%	13.9 min	1.0%
AA American Airlines	510	9%	69.2%	15.8 min	2.2%
DL Delta Air Lines	506	9%	82.2%	1.6 min	0.8%
YX Republic Airline	250	4%	62.8%	13.0 min	10.4%
OO SkyWest Airlines	228	4%	62.3%	42.6 min	1.8%
UA United Airlines	214	4%	53.3%	50.2 min	0.5%
MQ Envoy Air	130	2%	76.2%	10.0 min	0.8%
AS Alaska Airlines	92	2%	70.7%	7.2 min	1.1%
F9 Frontier Airlines	82	1%	65.9%	29.4 min	2.4%
OH PSA Airlines	54	1%	72.2%	46.6 min	11.1%
NK Spirit Airlines	39	1%	84.6%	1.3 min	0.0%

Busiest routes that month

Route	Cities	Flights	On time	Avg arrival delay	Cancelled
STL–DEN	St. Louis to Denver	352	63.6%	31.2 min	1.4%
STL–ATL	St. Louis to Atlanta	351	80.6%	4.0 min	0.6%
STL–ORD	St. Louis to Chicago	289	60.2%	29.2 min	1.7%
STL–LGA	St. Louis to New York	225	64.9%	10.4 min	8.4%
STL–DFW	St. Louis to Dallas/Fort Worth	222	64.0%	30.7 min	3.2%
STL–MCO	St. Louis to Orlando	209	71.8%	6.4 min	1.4%
STL–DCA	St. Louis to Washington	200	53.5%	39.3 min	7.0%
STL–DTW	St. Louis to Detroit	188	75.0%	14.5 min	1.1%
STL–CLT	St. Louis to Charlotte	170	74.1%	11.4 min	0.0%
STL–MDW	St. Louis to Chicago	169	67.5%	17.5 min	0.6%
STL–PHX	St. Louis to Phoenix	166	76.5%	12.1 min	0.0%
STL–LAS	St. Louis to Las Vegas	164	73.8%	15.7 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), July 2025.

Delay causes

BTS cause category	Share of delay minutes	National, Jul 2025	Minutes
Air carrier	30.6%	31.1%	36,408
Late-arriving aircraft	45.8%	40.8%	54,417
National Aviation System	19.5%	20.7%	23,182
Extreme weather	4.1%	7.3%	4,858
Security	0.1%	0.1%	78

118,943 delay minutes on 1,625 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 July 2025?

68.4% of 5,855 scheduled domestic departures left less than 15 minutes late, and 70.2% reached their destination on time. The national figures that month were 69.7% and 69.0%.

How does that compare with a year earlier?

In July 2024, 65.3% of 6,029 departures left on time and 1.9% were cancelled, against 68.4% and 1.6% in July 2025.

Provenance

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