Louisville Muhammad Ali International in August 2025

82.8%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 August 2025, reporting carriers scheduled 2,061 domestic departures from Louisville Muhammad Ali International (SDF). 82.8% left less than 15 minutes late and 82.0% reached their destination on time; 1.4% were cancelled.

Nationally that month, 76.8% of flights departed on time and 76.3% arrived on time, so SDF departures were 6.0 points above the national departure figure.

A year earlier, in August 2024, the airport had 2,057 departures with 80.7% leaving on time: a change of +2.1 points, with flights up 0%.

Flights arriving at SDF that month were on time 77.3% of the time (2,062 scheduled arrivals).

Of the delay minutes that carriers assigned to a BTS cause category that month, air carrier 47%, late-arriving aircraft 29% and national aviation system 18%.

On time 82.0%
Arrived 15+ minutes late 16.2%
Cancelled 1.4%
Diverted 0.4%

Every scheduled departure from SDF in August 2025, judged by arrival at the destination.

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

Measure	Aug 2025	Aug 2024	SDF, 12 months to Jul 2026	All reported flights, Aug 2025
Departed on time	82.8%	80.7%	80.0%	76.8%
Arrived on time	82.0%	79.8%	79.7%	76.3%
Cancelled	1.4%	2.3%	2.2%	1.1%
Average departure delay (late minutes only)	15.1 min	16.7 min	15.9 min	17.6 min
Scheduled departures a day	69	69	63	20,079
Scheduled departures	2,061	2,057	23,144	602,378

Airlines that month

Reporting carrier	Flights	Share	On time	Avg arrival delay	Cancelled
YX Republic Airline	432	21%	89.6%	-4.2 min	0.7%
WN Southwest Airlines	408	20%	83.6%	0.5 min	0.5%
OO SkyWest Airlines	258	13%	79.5%	10.7 min	2.3%
DL Delta Air Lines	241	12%	91.7%	-11.7 min	0.8%
OH PSA Airlines	219	11%	74.4%	6.0 min	4.1%
MQ Envoy Air	181	9%	76.2%	6.1 min	1.7%
AA American Airlines	125	6%	64.8%	61.4 min	2.4%
NK Spirit Airlines	74	4%	81.1%	-4.7 min	0.0%
UA United Airlines	62	3%	75.8%	3.6 min	0.0%
G4 Allegiant Air	61	3%	78.7%	11.1 min	0.0%

Busiest routes that month

Route	Cities	Flights	On time	Avg arrival delay	Cancelled
SDF–ORD	Louisville to Chicago	242	79.3%	3.9 min	3.3%
SDF–ATL	Louisville to Atlanta	241	91.7%	-11.7 min	0.8%
SDF–DFW	Louisville to Dallas/Fort Worth	185	64.3%	28.3 min	4.9%
SDF–CLT	Louisville to Charlotte	156	83.3%	4.6 min	0.6%
SDF–DTW	Louisville to Detroit	123	91.9%	-6.3 min	0.0%
SDF–DEN	Louisville to Denver	94	78.7%	1.4 min	0.0%
SDF–LGA	Louisville to New York	91	90.1%	-3.2 min	0.0%
SDF–MDW	Louisville to Chicago	90	90.0%	-5.9 min	1.1%
SDF–DCA	Louisville to Washington	88	80.7%	4.8 min	3.4%
SDF–MSP	Louisville to Minneapolis	81	84.0%	7.6 min	0.0%
SDF–BWI	Louisville to Baltimore	80	85.0%	2.7 min	1.3%
SDF–EWR	Louisville to Newark	65	83.1%	1.2 min	1.5%

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), August 2025.

Delay causes

BTS cause category	Share of delay minutes	National, Aug 2025	Minutes
Air carrier	47.2%	33.1%	14,114
Late-arriving aircraft	29.0%	40.5%	8,684
National Aviation System	18.0%	19.2%	5,394
Extreme weather	5.6%	7.0%	1,675
Security	0.1%	0.1%	27

29,894 delay minutes on 333 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 SDF on time in August 2025?

82.8% of 2,061 scheduled domestic departures left less than 15 minutes late, and 82.0% reached their destination on time. The national figures that month were 76.8% and 76.3%.

How does that compare with a year earlier?

In August 2024, 80.7% of 2,057 departures left on time and 2.3% were cancelled, against 82.8% and 1.4% in August 2025.

Provenance

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