RDU to STL flight delays & on-time performance
Nonstop flights from Raleigh-Durham International Airport to St. Louis Lambert International Airport · 668 miles · Aug 2025 – Jul 2026
No FAA-reported ground stops or delays at RDU or STL right now. Individual flights can still be delayed by the airline; check with your airline for your flight.
Key facts
- Flights from Raleigh/Durham (RDU) to St. Louis (STL) arrived on time 81% of the time in Aug 2025 – Jul 2026, better than the 78% national average.
- 0.3% were cancelled, and 5% arrived an hour or more late.
- Southwest Airlines is the only airline reporting nonstop flights on this route.
- Departures scheduled around 8am did best (96% on time); around 7pm did worst (47%).
- Tuesday was the most reliable day to fly (91% on time) and Thursday the least (71%).
- The largest source of delay minutes was late-arriving aircraft (60%).
Which airline is most on time from RDU 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 |
|---|---|---|---|---|---|
| Southwest Airlines | 81% | 0.3% | 11 min | 5.4% | 655 |
Best time of day to fly
On-time arrival rate by scheduled departure hour (local time).
- 6am95%149 flights
- 7am94%62 flights
- 8am96%85 flights
- 11am89%19 flights
- 5pm89%36 flights
- 6pm85%97 flights
- 7pm47%130 flights
- 8pm75%64 flights
Best day of the week
On-time arrival rate by day of departure.
- Monday79%0.0% cancelled
- Tuesday91%0.0% cancelled
- Wednesday85%0.0% cancelled
- Thursday71%0.0% cancelled
- Friday79%0.0% cancelled
- Saturday82%0.0% cancelled
- Sunday82%2.1% 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 aircraft60%
- Airline (crew, maintenance, cleaning, fueling)23%
- Air traffic control & airport congestion11%
- Extreme weather5%
- Security2%
Why flights are cancelled
Share of cancellations by reason.
- Extreme weather50%
- Air traffic control & airport congestion50%
- Airline (crew, maintenance, cleaning, fueling)0%
- Security0%
RDU to STL: common questions
- How often are RDU to STL flights on time?
- 81% 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 Raleigh/Durham to St. Louis cancelled?
- 0.3% of scheduled flights were cancelled (2 of 655).
- How long are typical delays?
- Across all flights the average arrival delay was 11 min (early arrivals count as zero). Flights that were late arrived 51 min behind schedule on average, and 5.4% of flights were an hour or more late.
- How long is taxi time at RDU?
- Flights on this route spent 11 min taxiing from the gate to takeoff on average.
Related routes
Return trip: STL to RDU — 81% on time
More flights from Raleigh/Durham
Data: U.S. DOT Bureau of Transportation Statistics, Aug 2025 – Jul 2026 (12 months). Latest month published by BTS: July 2026. Route: RDU → STL, nonstop flights by US airlines that report to the DOT. How we calculate this.