ONT · Ontario International Airport

Share of flights 15+ min late, by month

departures arrivals usual for the month (departures) Jan 2015 → Jul 2026; gridlines 10/20/30/40%

Month	Flights	Late 15+	vs usual	Cancelled	Avg min	Main cause
Jul 2026	2,377	22.5%	+1.1	0.9%	18	Airline
Jun 2026	2,304	26.4%	+4.4	1.0%	18	Late aircraft
May 2026	2,298	20.8%	+3.7	0.7%	13	Late aircraft
Apr 2026	2,119	19.0%	+1.4	0.3%	12	Late aircraft
Mar 2026	2,081	15.4%	+0.7	1.0%	10	Late aircraft
Feb 2026	1,734	15.2%	+2.3	0.3%	11	Late aircraft
Jan 2026	1,892	16.3%	+1.6	1.7%	14	Airline
Dec 2025	2,132	20.6%	-0.8	0.7%	15	Late aircraft
Nov 2025	2,184	17.5%	+3.2	2.1%	12	Late aircraft
Oct 2025	2,265	19.0%	+4.1	0.5%	13	Late aircraft
Sep 2025	2,177	15.1%	+0.9	0.5%	13	Airline
Aug 2025	2,291	18.4%	-1.4	0.8%	14	Late aircraft
Jul 2025	2,394	22.4%	+2.0	1.2%	18	Late aircraft
Jun 2025	2,307	22.0%	+2.0	0.9%	16	Late aircraft
May 2025	2,340	17.1%	-0.3	0.6%	14	Late aircraft
Apr 2025	2,250	13.5%	-4.1	0.4%	10	Late aircraft
Mar 2025	2,107	14.6%	-3.9	0.6%	9	Late aircraft
Feb 2025	1,774	11.9%	-4.2	0.8%	8	Late aircraft
Jan 2025	1,941	14.7%	+0.1	2.0%	12	Late aircraft
Dec 2024	2,116	15.4%	-6.0	0.3%	12	Late aircraft
Nov 2024	2,215	12.9%	-3.8	0.7%	9	Late aircraft
Oct 2024	2,388	11.6%	-4.1	0.3%	9	Late aircraft
Sep 2024	2,316	14.2%	+1.0	0.3%	10	Late aircraft
Aug 2024	2,428	14.2%	-5.7	0.9%	10	Late aircraft

Airline	Flights	Late	Canc.
SkyWest	176	7.4%	0.0%
Alaska	152	8.7%	1.3%
Delta	137	11.7%	0.0%
United	228	15.0%	0.4%
American	270	17.5%	0.7%
Frontier	160	24.4%	0.0%
Southwest	972	24.7%	0.1%

Airlines with 30+ departures that month.

Date	Flights	Late	Canc.
2015-09-16	58	69%	17%
2020-04-07	57	5%	67%
2020-03-31	69	12%	62%
2023-01-26	63	62%	11%
2022-12-23	66	53%	26%
2020-04-10	53	0%	64%
2025-01-08	55	52%	24%
2020-04-08	54	0%	63%
2020-04-03	61	4%	61%
2020-04-02	62	4%	60%
2022-12-26	67	35%	40%
2020-03-28	51	13%	55%

Departures; ranked by share late or cancelled.

None recorded.