Ontario International in January 2024

82.0%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 January 2024, reporting carriers scheduled 1,888 domestic departures from Ontario International (ONT). 82.0% left less than 15 minutes late and 83.2% reached their destination on time; 2.2% were cancelled.

Nationally that month, 74.0% of flights departed on time and 72.9% arrived on time, so ONT departures were 8.0 points above the national departure figure.

Flights arriving at ONT that month were on time 78.2% of the time (1,885 scheduled arrivals).

Of the delay minutes that carriers assigned to a BTS cause category that month, air carrier 44%, late-arriving aircraft 40% and national aviation system 13%.

On time 83.2%
Arrived 15+ minutes late 14.6%
Cancelled 2.2%
Diverted 0.1%

Every scheduled departure from ONT in January 2024, judged by arrival at the destination.

January 2024 against a year earlier, the airport's year and the nation

Measure	Jan 2024	Year earlier	ONT, 12 months to Jul 2026	All reported flights, Jan 2024
Departed on time	82.0%	—	80.3%	74.0%
Arrived on time	83.2%	—	81.2%	72.9%
Cancelled	2.2%	—	0.9%	3.7%
Average departure delay (late minutes only)	14.5 min	—	13.7 min	18.7 min
Scheduled departures a day	63	—	71	18,242
Scheduled departures	1,888	—	25,854	547,271

Airlines that month

Reporting carrier	Flights	Share	On time	Avg arrival delay	Cancelled
WN Southwest Airlines	890	47%	86.0%	0.3 min	1.0%
AA American Airlines	241	13%	78.8%	20.1 min	1.2%
DL Delta Air Lines	180	10%	94.4%	-10.5 min	0.6%
F9 Frontier Airlines	179	9%	82.1%	3.0 min	0.6%
OO SkyWest Airlines	156	8%	79.5%	2.5 min	0.0%
AS Alaska Airlines	110	6%	66.4%	-5.3 min	24.5%
UA United Airlines	62	3%	88.7%	-3.5 min	0.0%
HA Hawaiian Airlines	32	2%	59.4%	46.3 min	3.1%
B6 JetBlue Airways	31	2%	67.7%	48.3 min	0.0%
MQ Envoy Air	7	0%	85.7%	-9.4 min	0.0%

Busiest routes that month

Route	Cities	Flights	On time	Avg arrival delay	Cancelled
ONT–PHX	Ontario to Phoenix	254	83.9%	6.1 min	0.8%
ONT–DEN	Ontario to Denver	229	86.9%	-1.7 min	1.7%
ONT–LAS	Ontario to Las Vegas	197	82.2%	6.8 min	0.5%
ONT–DFW	Ontario to Dallas/Fort Worth	177	78.0%	18.2 min	1.7%
ONT–SEA	Ontario to Seattle	143	81.1%	-8.5 min	11.9%
ONT–OAK	Ontario to Oakland	135	91.1%	-3.9 min	0.0%
ONT–SMF	Ontario to Sacramento	133	81.2%	2.1 min	0.0%
ONT–SJC	Ontario to San Jose	110	89.1%	-3.3 min	0.0%
ONT–SFO	Ontario to San Francisco	98	73.5%	3.4 min	0.0%
ONT–SLC	Ontario to Salt Lake City	95	86.3%	-2.5 min	0.0%
ONT–ATL	Ontario to Atlanta	63	98.4%	-9.8 min	0.0%
ONT–PDX	Ontario to Portland	33	51.5%	1.1 min	33.3%

By scheduled departure hour

100

On-time share:under 62%6270768288% and over

Share of departures that left less than 15 minutes late, by scheduled hour (local time), January 2024.

Delay causes

BTS cause category	Share of delay minutes	National, Jan 2024	Minutes
Air carrier	43.5%	32.6%	10,220
Late-arriving aircraft	40.1%	39.0%	9,419
National Aviation System	12.8%	17.9%	2,995
Extreme weather	3.5%	10.3%	816
Security	0.1%	0.2%	32

23,482 delay minutes on 275 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 ONT on time in January 2024?

82.0% of 1,888 scheduled domestic departures left less than 15 minutes late, and 83.2% reached their destination on time. The national figures that month were 74.0% and 72.9%.

How does that compare with a year earlier?

January 2023 is outside the 36 months on file, or the airport had too few reported flights that month.

Provenance

Source: Bureau of Transportation Statistics, Reporting Carrier On-Time Performance, file for January 2024; public domain. Domestic scheduled flights by reporting carriers, totals and averages only. The site's data runs through July 2026. Full record for ONT · methodology · corrections.