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

Oakland, CA (OAK) to Ontario, CA (ONT) flight delay odds

82.1% of 1,489 official scheduled OAK-to-ONT flights arrived on time; 10.3% arrived at least 30 minutes late and 0.4% 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
82.1%arrived on time
10.3%30+ min late
0.4%cancelled
1,489scheduled 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 late1.2%all scheduled flights
Diverted0.1%did not reach as scheduled
Average arrival+1.9 mincompleted flights

Which departure time was most reliable for OAK to ONT?

Among qualifying OAK-to-ONT departure window results, Early morning had the highest on-time rate: 96.7% of 360 flights. Evening was lowest at 69.8% across 417 flights.

Departure windowFlightsOn time30+ minCancelled
Early morning36096.7%0.8%0.8%
Late morning26188.9%6.1%0.0%
Afternoon41679.1%12.0%0.2%
Evening41769.8%18.5%0.5%

Which weekday was most reliable for OAK to ONT?

Among qualifying OAK-to-ONT weekday results, Wednesday had the highest on-time rate: 86.2% of 203 flights. Thursday was lowest at 76.8% across 228 flights.

DayFlightsOn time30+ minCancelled
Monday22983.0%8.7%0.4%
Tuesday21184.4%9.5%0.0%
Wednesday20386.2%8.4%0.5%
Thursday22876.8%14.9%0.0%
Friday23079.1%11.7%0.9%
Saturday15685.3%7.7%0.6%
Sunday23281.9%10.3%0.4%

Which airline was most reliable for OAK to ONT?

Only Southwest Airlines met the OAK-to-ONT airline threshold: 82.1% of 1,489 scheduled flights arrived on time during July 2025–June 2026.

AirlineFlightsOn time30+ minCancelled
Southwest Airlines1,48982.1%10.3%0.4%

Which month was most reliable for OAK to ONT?

Among qualifying OAK-to-ONT month results, January 2026 had the highest on-time rate: 93.3% of 120 flights. June 2026 was lowest at 74.1% across 112 flights.

MonthFlightsOn time30+ minCancelled
July 202513485.8%9.7%0.0%
August 202513587.4%6.7%0.0%
September 202513387.2%7.5%0.0%
October 202513681.6%13.2%0.0%
November 202513080.8%8.5%3.1%
December 202512177.7%11.6%0.0%
January 202612093.3%3.3%0.8%
February 202611588.7%7.0%0.0%
March 202612177.7%15.7%0.8%
April 202611574.8%14.8%0.0%
May 202611774.4%12.8%0.0%
June 202611274.1%14.3%0.0%

What drove OAK to ONT delay minutes?

Late aircraft was the largest recorded OAK-to-ONT delay category, accounting for 57.5% of 12,733 BTS-attributed delay minutes during July 2025–June 2026.

Airline38.4%
Late aircraft57.5%
National airspace4.1%
Weather0.0%
Security0.0%
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.