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

Ontario, CA (ONT) to Seattle, WA (SEA) flight delay odds

Historically, 85.2% of scheduled reportable flights on this direction arrived on time in July 2025–June 2026. The sample includes 2,551 flights.

HISTORICAL ROUTE SIGNALLower disruption
85.2%arrived on time
7.7%30+ min late
1.3%cancelled
2,551scheduled flights
Based on July 2025–June 2026; on time means arrival less than 15 minutes late.
60+ minutes late3.5%all scheduled flights
120+ minutes late1.5%all scheduled flights
Diverted0.1%did not reach as scheduled
Average arrival-1.2 mincompleted flights

When is this route most reliable?

The same route can behave differently through the day. These are scheduled departure windows, not actual departure times. Small time windows with fewer than 40 flights are withheld.

Departure windowFlightsOn time30+ minCancelled
Early morning74493.0%3.4%0.4%
Late morning52890.7%4.9%1.5%
Afternoon74079.2%9.5%2.6%
Evening53077.0%14.2%0.6%

Weekday comparison

Day-of-week results use at least 30 scheduled flights per row. Look for broad patterns, not tiny percentage differences.

DayFlightsOn time30+ minCancelled
Monday38785.0%7.8%1.0%
Tuesday35687.6%5.9%0.0%
Wednesday34087.4%7.6%0.6%
Thursday37183.3%9.7%1.1%
Friday38381.2%9.4%3.4%
Saturday32486.7%6.8%1.2%
Sunday39085.6%6.4%1.5%

Airline comparison

Marketing-carrier results make codeshare flights easier to compare as travelers buy them. Dedicated route-airline reports require at least 160 flights.

AirlineFlightsOn time30+ minCancelled
Alaska Airlines1,26879.7%10.3%2.4%
SkyWest Airlines1,08591.7%4.2%0.3%
Frontier Airlines16982.8%11.2%0.0%
Delta Air Lines2993.1%3.4%0.0%

Monthly trend

Month-by-month results show whether a twelve-month average hides an unusual period.

MonthFlightsOn time30+ minCancelled
July 202530279.1%10.6%3.0%
August 202526683.1%10.2%0.8%
September 202521387.3%3.8%0.5%
October 202520084.0%8.5%1.0%
November 202521184.4%8.1%3.3%
December 202520080.5%12.0%1.0%
January 202615887.3%7.6%0.6%
February 202613595.6%3.0%0.0%
March 202617785.9%8.5%1.7%
April 202620090.5%4.0%0.5%
May 202624988.4%6.8%0.8%
June 202624083.3%6.2%1.2%

What drove reported delay minutes?

BTS cause minutes are reported for qualifying delayed flights. These shares describe recorded delay minutes—not the chance that a particular cause will affect your next flight.

Airline41.6%
Late aircraft37.3%
National airspace15.7%
Weather5.3%
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.