George Bush Intercontinental/Houston in September 2025

85.8%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 September 2025, reporting carriers scheduled 9,493 domestic departures from George Bush Intercontinental/Houston (IAH). 85.8% left less than 15 minutes late and 85.3% reached their destination on time; 0.2% were cancelled.

Nationally that month, 83.1% of flights departed on time and 82.8% arrived on time, so IAH departures were 2.7 points above the national departure figure.

A year earlier, in September 2024, the airport had 9,502 departures with 82.8% leaving on time: a change of +3.0 points, with flights down 0%.

Flights arriving at IAH that month were on time 86.8% of the time (9,489 scheduled arrivals).

Of the delay minutes that carriers assigned to a BTS cause category that month, air carrier 38%, late-arriving aircraft 35% and national aviation system 23%.

On time 85.3%
Arrived 15+ minutes late 14.3%
Cancelled 0.2%
Diverted 0.1%

Every scheduled departure from IAH in September 2025, judged by arrival at the destination.

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

Measure	Sep 2025	Sep 2024	IAH, 12 months to Jul 2026	All reported flights, Sep 2025
Departed on time	85.8%	82.8%	78.1%	83.1%
Arrived on time	85.3%	83.3%	77.6%	82.8%
Cancelled	0.2%	0.6%	1.1%	0.5%
Average departure delay (late minutes only)	11.1 min	11.3 min	17.2 min	12.2 min
Scheduled departures a day	316	317	326	18,748
Scheduled departures	9,493	9,502	119,020	562,439

Airlines that month

Reporting carrier	Flights	Share	On time	Avg arrival delay	Cancelled
UA United Airlines	5,940	63%	85.3%	-0.8 min	0.1%
OO SkyWest Airlines	936	10%	88.2%	-0.2 min	0.0%
DL Delta Air Lines	686	7%	91.4%	-7.4 min	0.3%
AA American Airlines	618	7%	81.7%	20.5 min	1.5%
NK Spirit Airlines	618	7%	84.8%	0.0 min	0.5%
F9 Frontier Airlines	309	3%	81.9%	4.7 min	0.0%
MQ Envoy Air	157	2%	77.1%	5.1 min	0.6%
AS Alaska Airlines	111	1%	89.2%	-3.6 min	0.0%
YX Republic Airline	82	1%	80.5%	1.3 min	0.0%
B6 JetBlue Airways	32	0%	37.5%	37.3 min	0.0%
OH PSA Airlines	4	0%	75.0%	-3.0 min	0.0%

Busiest routes that month

Route	Cities	Flights	On time	Avg arrival delay	Cancelled
IAH–ORD	Houston to Chicago	531	85.7%	-0.6 min	0.2%
IAH–DFW	Houston to Dallas/Fort Worth	498	79.3%	9.1 min	1.6%
IAH–LAX	Houston to Los Angeles	440	86.4%	-0.9 min	0.0%
IAH–ATL	Houston to Atlanta	384	90.9%	-7.9 min	0.3%
IAH–DEN	Houston to Denver	383	81.7%	0.4 min	0.3%
IAH–LGA	Houston to New York	369	85.4%	-3.9 min	0.3%
IAH–EWR	Houston to Newark	326	81.9%	3.8 min	0.0%
IAH–SFO	Houston to San Francisco	289	89.3%	-2.5 min	0.0%
IAH–MSY	Houston to New Orleans	280	91.8%	-8.6 min	0.0%
IAH–MIA	Houston to Miami	276	80.8%	10.3 min	0.4%
IAH–DCA	Houston to Washington	272	80.5%	1.6 min	0.0%
IAH–MCO	Houston to Orlando	271	90.0%	-2.6 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), September 2025.

Delay causes

BTS cause category	Share of delay minutes	National, Sep 2025	Minutes
Air carrier	38.2%	34.3%	35,836
Late-arriving aircraft	35.3%	37.4%	33,102
National Aviation System	23.1%	22.6%	21,718
Extreme weather	3.4%	5.6%	3,144
Security	0.0%	0.1%	18

93,818 delay minutes on 1,360 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 IAH on time in September 2025?

85.8% of 9,493 scheduled domestic departures left less than 15 minutes late, and 85.3% reached their destination on time. The national figures that month were 83.1% and 82.8%.

How does that compare with a year earlier?

In September 2024, 82.8% of 9,502 departures left on time and 0.6% were cancelled, against 85.8% and 0.2% in September 2025.

Provenance

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