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

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

83.8% of 537 official scheduled ONT-to-IAH flights arrived on time; 9.5% arrived at least 30 minutes late and 0.9% 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
83.8%arrived on time
9.5%30+ min late
0.9%cancelled
537scheduled flights
Based on July 2025–June 2026; on time means arrival less than 15 minutes late.
60+ minutes late5.4%all scheduled flights
120+ minutes late3.2%all scheduled flights
Diverted0.0%did not reach as scheduled
Average arrival+6.2 mincompleted flights

Which departure time was most reliable for ONT to IAH?

Among qualifying ONT-to-IAH departure window results, Early morning had the highest on-time rate: 88.9% of 377 flights. Evening was lowest at 67.7% across 65 flights.

Departure windowFlightsOn time30+ minCancelled
Early morning37788.9%6.6%0.5%
Afternoon9574.7%17.9%1.1%
Evening6567.7%13.8%3.1%

Which weekday was most reliable for ONT to IAH?

Among qualifying ONT-to-IAH weekday results, Thursday had the highest on-time rate: 89.2% of 74 flights. Monday was lowest at 77.3% across 97 flights.

DayFlightsOn time30+ minCancelled
Monday9777.3%16.5%0.0%
Tuesday6387.3%9.5%0.0%
Wednesday6388.9%3.2%1.6%
Thursday7489.2%5.4%0.0%
Friday10178.2%14.9%2.0%
Saturday6088.3%8.3%1.7%
Sunday7983.5%3.8%1.3%

Which airline was most reliable for ONT to IAH?

Among qualifying ONT-to-IAH airline results, United Airlines had the highest on-time rate: 89.3% of 365 flights. Frontier Airlines was lowest at 72.1% across 172 flights.

AirlineFlightsOn time30+ minCancelled
United Airlines36589.3%6.0%0.5%
Frontier Airlines17272.1%16.9%1.7%

Which month was most reliable for ONT to IAH?

Among qualifying ONT-to-IAH month results, February 2026 had the highest on-time rate: 100.0% of 36 flights. August 2025 was lowest at 72.5% across 40 flights.

MonthFlightsOn time30+ minCancelled
July 20253881.6%10.5%0.0%
August 20254072.5%22.5%0.0%
September 20254383.7%11.6%0.0%
October 20254889.6%6.2%0.0%
November 20254791.5%6.4%0.0%
December 20254477.3%13.6%0.0%
January 20264187.8%4.9%0.0%
February 202636100.0%0.0%0.0%
March 20264075.0%10.0%5.0%
April 20263994.9%5.1%0.0%
May 20266183.6%11.5%0.0%
June 20266073.3%10.0%5.0%

What drove ONT to IAH delay minutes?

Late aircraft was the largest recorded ONT-to-IAH delay category, accounting for 37.2% of 6,868 BTS-attributed delay minutes during July 2025–June 2026.

Airline36.9%
Late aircraft37.2%
National airspace24.8%
Weather1.1%
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.