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

Ontario, CA (ONT) to San Francisco, CA (SFO) flight delay odds

Historically, 64.4% of scheduled reportable flights on this direction arrived on time in July 2025–June 2026. The sample includes 1,290 flights.

HISTORICAL ROUTE SIGNALVariable
64.4%arrived on time
25.1%30+ min late
0.8%cancelled
1,290scheduled flights
Based on July 2025–June 2026; on time means arrival less than 15 minutes late.
60+ minutes late12.4%all scheduled flights
120+ minutes late4.5%all scheduled flights
Diverted0.0%did not reach as scheduled
Average arrival+17.6 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 morning34885.9%7.2%1.1%
Late morning11145.0%43.2%0.0%
Afternoon34373.2%15.7%0.0%
Evening38044.7%42.4%0.8%
Night10856.5%33.3%2.8%

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
Monday20557.6%28.8%0.5%
Tuesday16074.4%16.2%0.6%
Wednesday15563.2%27.1%0.0%
Thursday19160.7%26.2%1.6%
Friday20763.8%28.5%0.5%
Saturday16374.2%17.2%0.6%
Sunday20960.8%28.7%1.4%

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
United Airlines1,00770.4%19.4%0.4%
Frontier Airlines17740.7%48.6%2.3%
SkyWest Airlines10647.2%40.6%1.9%

Monthly trend

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

MonthFlightsOn time30+ minCancelled
July 202510475.0%15.4%0.0%
August 202510970.6%19.3%0.9%
September 202510864.8%22.2%0.0%
October 202511457.9%24.6%0.0%
November 202510574.3%19.0%1.9%
December 202510474.0%17.3%1.9%
January 20269381.7%15.1%1.1%
February 20267972.2%20.3%0.0%
March 202610389.3%5.8%1.9%
April 202612453.2%34.7%0.0%
May 202612742.5%46.5%1.6%
June 202612033.3%49.2%0.0%

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.

Airline15.3%
Late aircraft25.4%
National airspace56.6%
Weather2.7%
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.