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

Houston, TX (IAH) to Ontario, CA (ONT) flight delay odds

Historically, 75.5% of scheduled reportable flights on this direction arrived on time in July 2025–June 2026. The sample includes 538 flights.

HISTORICAL ROUTE SIGNALGenerally reliable
75.5%arrived on time
16.0%30+ min late
0.2%cancelled
538scheduled flights
Based on July 2025–June 2026; on time means arrival less than 15 minutes late.
60+ minutes late8.7%all scheduled flights
120+ minutes late3.3%all scheduled flights
Diverted0.2%did not reach as scheduled
Average arrival+6.3 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
Afternoon8070.0%16.2%0.0%
Evening41174.9%17.0%0.2%

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
Monday9769.1%22.7%1.0%
Tuesday6385.7%7.9%0.0%
Wednesday6373.0%17.5%0.0%
Thursday7475.7%14.9%0.0%
Friday10273.5%19.6%0.0%
Saturday6078.3%15.0%0.0%
Sunday7977.2%10.1%0.0%

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 Airlines36577.5%15.6%0.0%
Frontier Airlines17371.1%16.8%0.6%

Monthly trend

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

MonthFlightsOn time30+ minCancelled
July 20253956.4%35.9%0.0%
August 20254060.0%20.0%2.5%
September 20254381.4%14.0%0.0%
October 20254868.8%10.4%0.0%
November 20254768.1%21.3%0.0%
December 20254470.5%11.4%0.0%
January 20264190.2%4.9%0.0%
February 20263691.7%8.3%0.0%
March 20264080.0%15.0%0.0%
April 20263984.6%15.4%0.0%
May 20266185.2%9.8%0.0%
June 20266070.0%25.0%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.

Airline30.3%
Late aircraft58.0%
National airspace9.1%
Weather2.6%
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.