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

Houston, TX (IAH) to St. Louis, MO (STL) flight delay odds

73.7% of 426 official scheduled IAH-to-STL flights arrived on time; 16.9% arrived at least 30 minutes late and 0.7% 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 SIGNALGenerally reliable
73.7%arrived on time
16.9%30+ min late
0.7%cancelled
426scheduled flights
Based on July 2025–June 2026; on time means arrival less than 15 minutes late.
60+ minutes late7.0%all scheduled flights
120+ minutes late2.6%all scheduled flights
Diverted0.5%did not reach as scheduled
Average arrival+11.0 mincompleted flights

Which departure time was most reliable for IAH to STL?

Among qualifying IAH-to-STL departure window results, Evening had the highest on-time rate: 75.1% of 285 flights. Afternoon was lowest at 72.3% across 137 flights.

Departure windowFlightsOn time30+ minCancelled
Afternoon13772.3%19.0%0.7%
Evening28575.1%15.4%0.7%

Which weekday was most reliable for IAH to STL?

Among qualifying IAH-to-STL weekday results, Tuesday had the highest on-time rate: 79.2% of 48 flights. Saturday was lowest at 69.4% across 49 flights.

DayFlightsOn time30+ minCancelled
Monday6371.4%15.9%0.0%
Tuesday4879.2%8.3%0.0%
Wednesday6078.3%15.0%1.7%
Thursday7369.9%20.5%0.0%
Friday5777.2%15.8%0.0%
Saturday4969.4%18.4%4.1%
Sunday7672.4%21.1%0.0%

Which airline was most reliable for IAH to STL?

Among qualifying IAH-to-STL airline results, United Airlines had the highest on-time rate: 74.4% of 359 flights. SkyWest Airlines was lowest at 70.1% across 67 flights.

AirlineFlightsOn time30+ minCancelled
United Airlines35974.4%15.6%0.8%
SkyWest Airlines6770.1%23.9%0.0%

Which month was most reliable for IAH to STL?

Among qualifying IAH-to-STL month results, April 2026 had the highest on-time rate: 86.7% of 30 flights. August 2025 was lowest at 62.2% across 37 flights.

MonthFlightsOn time30+ minCancelled
July 20253262.5%28.1%0.0%
August 20253762.2%27.0%0.0%
September 20255080.0%8.0%0.0%
October 20255172.5%9.8%0.0%
November 20254967.3%22.4%0.0%
December 20253375.8%21.2%0.0%
January 20263582.9%8.6%5.7%
February 20262979.3%10.3%0.0%
March 20263171.0%22.6%3.2%
April 20263086.7%6.7%0.0%
May 20262969.0%24.1%0.0%
June 20262080.0%20.0%0.0%

What drove IAH to STL delay minutes?

Late aircraft was the largest recorded IAH-to-STL delay category, accounting for 51.5% of 6,511 BTS-attributed delay minutes during July 2025–June 2026.

Airline31.7%
Late aircraft51.5%
National airspace12.1%
Weather4.7%
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.