BTS DATA COMPLETE THROUGH JUNE 2026HISTORICAL ODDS · NOT LIVE FLIGHT STATUS
DelayOddsKnow the route before you book
ONT→SJC

Ontario, CA (ONT) to San Jose, CA (SJC) flight delay odds

85.1% of 1,318 official scheduled ONT-to-SJC flights arrived on time; 9.1% arrived at least 30 minutes late and 0.1% were cancelled during July 2025–June 2026.

Source: U.S. Bureau of Transportation Statistics · Reporting window: July 2025–June 2026 · Updated September 16, 2026

HISTORICAL ROUTE SIGNALLower disruption
85.1%arrived on time
9.1%30+ min late
0.1%cancelled
1,318scheduled flights
Based on July 2025–June 2026; on time means arrival less than 15 minutes late.
60+ minutes late4.3%all scheduled flights
120+ minutes late1.7%all scheduled flights
Diverted0.0%did not reach as scheduled
Average arrival-0.3 mincompleted flights

Which departure time was most reliable for ONT to SJC?

Among qualifying ONT-to-SJC departure window results, Early morning had the highest on-time rate: 97.3% of 330 flights. Evening was lowest at 72.1% across 373 flights.

Departure windowFlightsOn time30+ minCancelled
Early morning33097.3%1.8%0.3%
Late morning23794.5%3.0%0.0%
Afternoon36682.8%10.4%0.0%
Evening37372.1%16.9%0.0%

Which weekday was most reliable for ONT to SJC?

Among qualifying ONT-to-SJC weekday results, Tuesday had the highest on-time rate: 89.4% of 179 flights. Sunday was lowest at 78.1% across 201 flights.

DayFlightsOn time30+ minCancelled
Monday20684.5%9.7%0.0%
Tuesday17989.4%6.1%0.6%
Wednesday17288.4%6.4%0.0%
Thursday20286.1%8.4%0.0%
Friday20283.2%10.4%0.0%
Saturday15687.2%9.6%0.0%
Sunday20178.1%12.4%0.0%

Which airline was most reliable for ONT to SJC?

Only Southwest Airlines met the ONT-to-SJC airline threshold: 85.1% of 1,318 scheduled flights arrived on time during July 2025–June 2026.

AirlineFlightsOn time30+ minCancelled
Southwest Airlines1,31885.1%9.1%0.1%

Which month was most reliable for ONT to SJC?

Among qualifying ONT-to-SJC month results, January 2026 had the highest on-time rate: 94.1% of 101 flights. June 2026 was lowest at 75.4% across 114 flights.

MonthFlightsOn time30+ minCancelled
July 202511877.1%11.9%0.0%
August 202511088.2%7.3%0.0%
September 202510786.0%11.2%0.0%
October 202511078.2%10.9%0.0%
November 202511883.9%11.0%0.0%
December 202511889.8%5.9%0.8%
January 202610194.1%4.0%0.0%
February 20269990.9%6.1%0.0%
March 202610783.2%15.0%0.0%
April 202610684.0%7.5%0.0%
May 202611091.8%1.8%0.0%
June 202611475.4%15.8%0.0%

What drove ONT to SJC delay minutes?

Late aircraft was the largest recorded ONT-to-SJC delay category, accounting for 76.1% of 10,901 BTS-attributed delay minutes during July 2025–June 2026.

Airline21.7%
Late aircraft76.1%
National airspace2.0%
Weather0.0%
Security0.1%
This is historical evidence, not a forecast.

Weather, schedules and operations change. For a trip you have already booked, use the airline or airport for live status.