IAH to STL flight delays & on-time performance
Nonstop flights from George Bush Intercontinental Airport to St. Louis Lambert International Airport · 667 miles · Aug 2025 – Jul 2026
No FAA-reported ground stops or delays at IAH or STL right now. Individual flights can still be delayed by the airline; check with your airline for your flight.
Key facts
- Flights from Houston (IAH) to St. Louis (STL) arrived on time 75% of the time in Aug 2025 – Jul 2026, worse than the 78% national average.
- 0.7% were cancelled, and 7% arrived an hour or more late.
- United Airlines was the most punctual airline here (76% on time); SkyWest Airlines was the least (73%).
- Departures scheduled around 7pm did best (81% on time); around 5pm did worst (72%).
- Wednesday was the most reliable day to fly (85% on time) and Thursday the least (66%).
- The largest source of delay minutes was late-arriving aircraft (52%).
Which airline is most on time from IAH to STL?
Ranked by on-time arrival rate. Regional airlines fly under their partner's brand (e.g. SkyWest for Delta Connection or United Express).
| Airline | On time | Cancelled | Avg delay | 1 hr+ late | Flights |
|---|---|---|---|---|---|
| United Airlines | 76% | 0.8% | 15 min | 5.7% | 354 |
| SkyWest AirlinesRegional airline operating flights for United Express, Delta Connection, American Eagle and Alaska. | 73% | 0.0% | 21 min | 10.6% | 66 |
Best time of day to fly
On-time arrival rate by scheduled departure hour (local time).
- 12pm73%51 flights
- 2pm75%16 flights
- 4pm75%65 flights
- 5pm72%18 flights
- 7pm81%104 flights
- 8pm73%152 flights
Best day of the week
On-time arrival rate by day of departure.
- Monday73%0.0% cancelled
- Tuesday82%0.0% cancelled
- Wednesday85%1.7% cancelled
- Thursday66%0.0% cancelled
- Friday77%0.0% cancelled
- Saturday76%3.8% cancelled
- Sunday74%0.0% cancelled
On-time trend by month
Why flights are late
Share of delay minutes by cause, as reported by airlines to the DOT.
- Late-arriving aircraft52%
- Airline (crew, maintenance, cleaning, fueling)34%
- Air traffic control & airport congestion12%
- Extreme weather2%
- Security0%
Why flights are cancelled
Share of cancellations by reason.
- Extreme weather100%
- Airline (crew, maintenance, cleaning, fueling)0%
- Air traffic control & airport congestion0%
- Security0%
IAH to STL: common questions
- How often are IAH to STL flights on time?
- 75% of flights arrived less than 15 minutes late in Aug 2025 – Jul 2026, compared with 78% for all US flights.
- How often are flights from Houston to St. Louis cancelled?
- 0.7% of scheduled flights were cancelled (3 of 420).
- How long are typical delays?
- Across all flights the average arrival delay was 16 min (early arrivals count as zero). Flights that were late arrived 59 min behind schedule on average, and 6.5% of flights were an hour or more late.
- How long is taxi time at IAH?
- Flights on this route spent 23 min taxiing from the gate to takeoff on average.
Related routes
Return trip: STL to IAH — 81% on time
More flights from Houston
Data: U.S. DOT Bureau of Transportation Statistics, Aug 2025 – Jul 2026 (12 months). Latest month published by BTS: July 2026. Route: IAH → STL, nonstop flights by US airlines that report to the DOT. How we calculate this.