BWI to STL flight delays & on-time performance
Nonstop flights from Baltimore/Washington International Thurgood Marshall Airport to St. Louis Lambert International Airport · 738 miles · Aug 2025 – Jul 2026
No FAA-reported ground stops or delays at BWI or STL right now. Individual flights can still be delayed by the airline; check with your airline for your flight.
Key facts
- Flights from Baltimore (BWI) to St. Louis (STL) arrived on time 82% of the time in Aug 2025 – Jul 2026, better than the 78% national average.
- 1.1% 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 6am did best (93% on time); around 7pm did worst (59%).
- Tuesday was the most reliable day to fly (88% on time) and Sunday the least (76%).
- The largest source of delay minutes was late-arriving aircraft (50%).
Which airline is most on time from BWI 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 | 82% | 1.1% | 11 min | 5.3% | 1,268 |
Best time of day to fly
On-time arrival rate by scheduled departure hour (local time).
- 6am93%195 flights
- 7am91%143 flights
- 8am97%32 flights
- 9am85%89 flights
- 10am88%72 flights
- 11am93%45 flights
- 1pm87%47 flights
- 2pm78%82 flights
- 3pm86%77 flights
- 4pm71%17 flights
- 5pm78%47 flights
- 6pm78%90 flights
- 7pm59%85 flights
- 8pm76%59 flights
- 9pm66%107 flights
- 10pm79%78 flights
Best day of the week
On-time arrival rate by day of departure.
- Monday82%0.5% cancelled
- Tuesday88%0.6% cancelled
- Wednesday83%0.6% cancelled
- Thursday85%1.0% cancelled
- Friday85%1.0% cancelled
- Saturday80%0.0% cancelled
- Sunday76%3.6% 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 aircraft50%
- Airline (crew, maintenance, cleaning, fueling)34%
- Air traffic control & airport congestion13%
- Extreme weather2%
- Security1%
Why flights are cancelled
Share of cancellations by reason.
- Extreme weather79%
- Airline (crew, maintenance, cleaning, fueling)14%
- Air traffic control & airport congestion7%
- Security0%
BWI to STL: common questions
- How often are BWI to STL flights on time?
- 82% 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 Baltimore to St. Louis cancelled?
- 1.1% of scheduled flights were cancelled (14 of 1,268).
- 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 56 min behind schedule on average, and 5.3% of flights were an hour or more late.
- How long is taxi time at BWI?
- Flights on this route spent 14 min taxiing from the gate to takeoff on average.
Related routes
Return trip: STL to BWI — 80% on time
More flights from Baltimore
Data: U.S. DOT Bureau of Transportation Statistics, Aug 2025 – Jul 2026 (12 months). Latest month published by BTS: July 2026. Route: BWI → STL, nonstop flights by US airlines that report to the DOT. How we calculate this.