Chicago O'Hare International in August 2025

71.0%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 30,090 domestic departures from Chicago O'Hare International (ORD). 71.0% left less than 15 minutes late and 71.8% reached their destination on time; 2.5% were cancelled.

Nationally that month, 76.8% of flights departed on time and 76.3% arrived on time, so ORD departures were 5.8 points below the national departure figure.

A year earlier, in August 2024, the airport had 25,500 departures with 70.1% leaving on time: a change of +0.9 points, with flights up 18%.

Flights arriving at ORD that month were on time 70.9% of the time (30,098 scheduled arrivals).

Of the delay minutes that carriers assigned to a BTS cause category that month, late-arriving aircraft 42%, air carrier 31% and national aviation system 15%.

On time 71.8%
Arrived 15+ minutes late 25.4%
Cancelled 2.5%
Diverted 0.3%

Every scheduled departure from ORD 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	ORD, 12 months to Jul 2026	All reported flights, Aug 2025
Departed on time	71.0%	70.1%	71.4%	76.8%
Arrived on time	71.8%	68.1%	69.4%	76.3%
Cancelled	2.5%	1.4%	2.8%	1.1%
Average departure delay (late minutes only)	22.9 min	23.0 min	22.3 min	17.6 min
Scheduled departures a day	1,003	850	986	20,079
Scheduled departures	30,090	25,500	359,911	602,378

Airlines that month

Reporting carrier	Flights	Share	On time	Avg arrival delay	Cancelled
UA United Airlines	8,616	29%	72.3%	13.1 min	1.9%
OO SkyWest Airlines	6,574	22%	69.7%	16.3 min	3.5%
AA American Airlines	5,499	18%	63.6%	25.2 min	2.7%
MQ Envoy Air	4,295	14%	79.1%	2.2 min	2.5%
YX Republic Airline	2,047	7%	79.8%	4.8 min	2.5%
DL Delta Air Lines	1,075	4%	78.2%	12.0 min	1.2%
NK Spirit Airlines	504	2%	78.6%	12.0 min	0.8%
WN Southwest Airlines	408	1%	72.1%	13.6 min	0.7%
F9 Frontier Airlines	353	1%	69.7%	20.3 min	2.3%
AS Alaska Airlines	327	1%	69.7%	7.6 min	1.5%
OH PSA Airlines	281	1%	61.2%	51.1 min	4.3%
B6 JetBlue Airways	111	0%	88.3%	-0.7 min	0.9%

Busiest routes that month

Route	Cities	Flights	On time	Avg arrival delay	Cancelled
ORD–LGA	Chicago to New York	973	68.4%	17.9 min	3.1%
ORD–BOS	Chicago to Boston	685	72.1%	14.3 min	2.2%
ORD–LAX	Chicago to Los Angeles	664	71.1%	18.0 min	1.7%
ORD–SEA	Chicago to Seattle	602	67.1%	14.6 min	2.0%
ORD–DEN	Chicago to Denver	598	71.1%	13.8 min	1.5%
ORD–DCA	Chicago to Washington	585	69.4%	17.9 min	2.7%
ORD–DFW	Chicago to Dallas/Fort Worth	582	62.7%	25.8 min	3.4%
ORD–ATL	Chicago to Atlanta	573	76.6%	9.6 min	1.7%
ORD–MSP	Chicago to Minneapolis	542	68.5%	20.1 min	0.9%
ORD–IAH	Chicago to Houston	531	70.6%	14.8 min	2.1%
ORD–SFO	Chicago to San Francisco	523	70.9%	14.0 min	2.7%
ORD–DTW	Chicago to Detroit	499	76.8%	7.9 min	2.2%

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	31.1%	33.1%	190,908
Late-arriving aircraft	41.5%	40.5%	254,650
National Aviation System	14.9%	19.2%	91,327
Extreme weather	12.2%	7.0%	74,887
Security	0.2%	0.1%	1,110

612,882 delay minutes on 7,648 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 ORD on time in August 2025?

71.0% of 30,090 scheduled domestic departures left less than 15 minutes late, and 71.8% 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, 70.1% of 25,500 departures left on time and 1.4% were cancelled, against 71.0% and 2.5% 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 ORD · methodology · corrections.