STL to IAH flight delays
St. Louis, MO (STL) Houston, TX (IAH) · 667 miles
1,131 flights · July 2024 – July 2026 · US Bureau of Transportation Statistics
77.3%
Arrived on time
Within 15 minutes of schedule
1.59%
Cancelled
Share of scheduled flights
83 min
When late, late by
Average across delayed arrivals
20 min
Delay per flight
Averaged over every flight flown
What the record says about this route
The season swings this route hard. In September it ran 42.3 points more punctual than in July — a difference bigger than the one between the best and worst airlines on most routes. If the date is flexible, it is worth more than the carrier.
The 2 airlines here are separated by under 5 points — close enough to call a tie. Choose on price and departure time.
The St. Louis to Houston route sits close to the middle of the record — neither notably punctual nor notably late.
Which airline should you fly on this route?
Over July 2024 – July 2026, United Airlines arrived on time most often on STL to IAH. SkyWest Airlines was late most often. Flights ran closest to schedule in September and worst in July.
Every airline on STL to IAH
Ranked by how many flights each one operated. A carrier with fewer than 100 flights in the period is listed but not graded.
| Airline | Flights | On time | Cancelled | Avg delay | Grade |
|---|---|---|---|---|---|
| United Airlines | 986 | 77.95% | 1.83% | 77 min | C |
| SkyWest Airlines | 145 | 72.92% | 0% | 119 min | C |
Month by month
Share of flights that arrived within 15 minutes of schedule, by month flown.
The return leg
IAH to STL Houston back to St. Louis 72.68% on time DOther routes from St. Louis
Common questions
Are flights from St. Louis to Houston usually delayed?
77.3% of flights on the STL to IAH route arrived within 15 minutes of schedule, so roughly 2 in every ten arrived late. That is about the same as the average route in this record.
Which airline is most on time from St. Louis to Houston?
United Airlines, at 77.95% on time across 986 flights. The least punctual on the route was SkyWest Airlines at 72.92%.
How often are STL to IAH flights cancelled?
1.59% of scheduled flights did not operate — about 16 in every thousand. That is in the normal range.
What is the best month to fly St. Louis to Houston?
September, when 94.1% of flights arrived on time. The worst was July at 51.8%.
When STL to IAH flights are late, how late are they?
About 83 minutes on average across the flights that arrived more than 15 minutes behind schedule.
What these figures do and do not tell you
Everything on this page is counted from the flights that actually operated on STL to IAH during July 2024 – July 2026, as reported by the airlines to the US Bureau of Transportation Statistics. "On time" is the federal definition: arriving at the gate within 15 minutes of the scheduled time.
A route's record is a description of the past, not a forecast. Weather, air traffic control and the aircraft's earlier flights that day drive most delays, and none of them are predictable from a historical rate. What the record does tell you is whether this route runs late more often than others, and which carrier on it has the better history — which is the part you can actually act on when you book.
Cancellations are counted separately from delays because they are a different problem for a traveller: a late flight still gets you there. How the grade is calculated →