Route · STL → IAH · 2020–2025 BTS data
St. Louis to Houston
According to PlainFlights' route traffic ranking (BTS On-Time Performance total flights), STL to IAH (St. Louis to Houston) ranks #2822 of 4927 tracked domestic routes by total flights (most flights = #1).
Data updated 2026-06-13
- 82.9%
- On-time
- +3.9 pts
- vs US avg
- 87 min
- Delay when late
- 4,208
- Flights
- #2822 of 4927
- Corpus placement
Cancelled
1.9%
Best Month
Sep 2025 94%
Worst Month
Jul 2024 56%
Distance
667 mi
Carriers
14
Monthly Performance
Recent 24 months of route data.
| Period | Flights | Delayed | Cancelled | Diverted | Carriers |
|---|---|---|---|---|---|
| Dec 2025 | 34 | 9 | 0 | 0 | UA |
| Nov 2025 | 49 | 8 | 1 | 0 | OO,UA |
| Oct 2025 | 50 | 9 | 0 | 0 | UA |
| Sep 2025 | 51 | 3 | 0 | 0 | UA |
| Aug 2025 | 37 | 6 | 1 | 0 | OO,UA |
| Jul 2025 | 31 | 11 | 0 | 0 | OO,UA |
| Jun 2025 | 49 | 17 | 0 | 1 | OO,UA |
| May 2025 | 59 | 15 | 2 | 0 | UA |
| Apr 2025 | 90 | 15 | 0 | 1 | OO,UA |
| Mar 2025 | 34 | 10 | 0 | 0 | OO,UA |
| Feb 2025 | 39 | 13 | 0 | 0 | UA |
| Jan 2025 | 56 | 9 | 5 | 0 | UA |
| Dec 2024 | 58 | 15 | 1 | 0 | UA |
| Nov 2024 | 61 | 11 | 0 | 0 | OO,UA |
| Oct 2024 | 63 | 8 | 0 | 0 | UA |
| Sep 2024 | 60 | 9 | 1 | 0 | UA |
| Aug 2024 | 73 | 21 | 0 | 0 | OO,UA |
| Jul 2024 | 61 | 27 | 4 | 1 | OO,UA |
| Jun 2024 | 84 | 13 | 1 | 1 | OO,UA |
| May 2024 | 43 | 23 | 1 | 1 | OO,UA |
| Apr 2024 | 60 | 12 | 0 | 0 | UA |
| Mar 2024 | 54 | 12 | 0 | 0 | UA |
| Feb 2024 | 56 | 6 | 1 | 0 | UA |
| Jan 2024 | 73 | 12 | 7 | 0 | OO,UA |
STL–IAH seasonal on-time pattern
Best: September (92.1%) · weakest: July (72.7%)
Strongest calendar month
September
92.1% on-time · ~74 flights/mo
Busiest calendar month
January
~74 flights/mo avg
Weakest calendar month
July
72.7% on-time · ~62 flights/mo
Cancellation Rate
1.9%
25 of 1,325 flights
Diversion Rate
0.4%
5 of 1,325 flights
Explore origin & destination
On-time and delay data for the airports this route connects.
STL - St. Louis
Full on-time, delay-cause, and seasonal performance for St. Louis, MO.
STL on-time profileIAH - Houston
Full on-time, delay-cause, and seasonal performance for Houston, TX.
IAH on-time profileCompare the two airports
See STL and IAH side by side on delays, cancellations, and reliability.
Compare STL vs IAHOrigin-hub reliability standing
Mid-pack among STL departures
From STL, this corridor sits with 45 other 75–85% on-time routes out of 51 tracked departures, not the hub's reliability leaders (5 at ≥85%) and not the softest ( 1 below 75%). Destination: Houston · fleet on-time rank #2012 of 4927.
Similar routes
Other BTS-tracked routes with comparable performance or trip length to STL–IAH.
Routes with a similar on-time rate
What the Data Says About STL to IAH
Bureau of Transportation Statistics records show St. Louis to Houston (STL to IAH) running a 82.9% on-time rate over 4,208 tracked flights, on the stronger end of a typical domestic pairing. When flights do run late, the average delay is 86.7 minutes. The 667-mile corridor is served by 14 carriers, and over the last 24 months 1.9% of 1,325 flights were cancelled, 0.4% diverted.
The monthly split is wide on this route: Sep 2025 posted the strongest performance at 94% on-time, while Jul 2024 came in at just 56% - a 38-point swing worth factoring into travel timing.
On the multi-year calendar, STL–IAH peaks in September at 92.1% on-time while January carries the heaviest traffic (~74 flights per month) ; the softest month is July at 72.7%, a 19.4-point swing that repeats because the corridor's weather and holiday mix stays stable year to year.
Frequently Asked Questions
Where does STL to IAH rank among US routes by traffic? ▼
How often are flights delayed from STL to IAH? ▼
What is the cancellation rate for STL to IAH? ▼
How far is the flight from STL to IAH? ▼
When is the best time to fly from STL to IAH? ▼
Airports on this route
Data source
Data Source: Bureau of Transportation Statistics (BTS), On-Time Performance Data. Statistics reflect cumulative performance across all available reporting periods.
Read our methodology - how this data is sourced, computed, and verified.
Using STL–IAH data
STL–IAH runs 3.9 pts above the national 79% average; the remaining risk is month-to-month swing and carrier mix, not a weak headline rate.
- Compare STL and IAH airport profiles: delay causes and top routes differ even on the same corridor. STL airport
- If your dates flex, September (92.1% on-time) beats July (72.7%) on this corridor. Seasonal chart
- 4 other routes post a similar 82.9% on-time rate; compare before you commit to this pairing. Similar routes
On-time rate reflects the BTS historical average across all reporting carriers on this origin–destination pair, not any single flight or booking recommendation.
Every figure on PlainFlights is rendered directly from BTS On-Time Performance data, no number is typed in by an editor. This page aggregates this specific route's on-time performance and monthly trend, live from the dataset. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.