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

Ontario, CA (ONT) to Portland, OR (PDX) flight delay odds

88.5% of 550 official scheduled ONT-to-PDX flights arrived on time; 6.9% arrived at least 30 minutes late and 0.5% 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
88.5%arrived on time
6.9%30+ min late
0.5%cancelled
550scheduled flights
Based on July 2025–June 2026; on time means arrival less than 15 minutes late.
60+ minutes late3.8%all scheduled flights
120+ minutes late1.1%all scheduled flights
Diverted0.0%did not reach as scheduled
Average arrival-5.5 mincompleted flights

Which departure time was most reliable for ONT to PDX?

Among qualifying ONT-to-PDX departure window results, Early morning had the highest on-time rate: 91.5% of 281 flights. Afternoon was lowest at 75.0% across 56 flights.

Departure windowFlightsOn time30+ minCancelled
Early morning28191.5%5.0%0.7%
Late morning4987.8%6.1%0.0%
Afternoon5675.0%16.1%0.0%
Evening16488.4%7.3%0.6%

Which weekday was most reliable for ONT to PDX?

Among qualifying ONT-to-PDX weekday results, Monday had the highest on-time rate: 93.9% of 98 flights. Thursday was lowest at 84.0% across 75 flights.

DayFlightsOn time30+ minCancelled
Monday9893.9%3.1%0.0%
Tuesday7485.1%6.8%1.4%
Wednesday5589.1%7.3%0.0%
Thursday7584.0%13.3%0.0%
Friday9485.1%8.5%2.1%
Saturday7090.0%7.1%0.0%
Sunday8491.7%3.6%0.0%

Which airline was most reliable for ONT to PDX?

Among qualifying ONT-to-PDX airline results, SkyWest Airlines had the highest on-time rate: 91.9% of 62 flights. Frontier Airlines was lowest at 75.6% across 86 flights.

AirlineFlightsOn time30+ minCancelled
Alaska Airlines40290.8%6.0%0.7%
Frontier Airlines8675.6%12.8%0.0%
SkyWest Airlines6291.9%4.8%0.0%

Which month was most reliable for ONT to PDX?

Among qualifying ONT-to-PDX month results, June 2026 had the highest on-time rate: 96.1% of 51 flights. October 2025 was lowest at 76.7% across 43 flights.

MonthFlightsOn time30+ minCancelled
July 20252676.9%15.4%0.0%
August 20253976.9%12.8%0.0%
September 20256191.8%1.6%0.0%
October 20254376.7%9.3%2.3%
November 20256789.6%7.5%1.5%
December 20254488.6%6.8%0.0%
January 20266191.8%8.2%0.0%
February 20264795.7%2.1%0.0%
March 20263886.8%13.2%0.0%
April 20263591.4%5.7%2.9%
May 20263889.5%2.6%0.0%
June 20265196.1%3.9%0.0%

What drove ONT to PDX delay minutes?

Airline was the largest recorded ONT-to-PDX delay category, accounting for 39.5% of 3,656 BTS-attributed delay minutes during July 2025–June 2026.

Airline39.5%
Late aircraft38.6%
National airspace21.9%
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.