STL to IAD flight delays & on-time performance
Nonstop flights from St. Louis Lambert International Airport to Washington Dulles International Airport · 696 miles · Aug 2025 – Jul 2026
No FAA-reported ground stops or delays at STL or IAD right now. Individual flights can still be delayed by the airline; check with your airline for your flight.
Key facts
- Flights from St. Louis (STL) to Washington (IAD) arrived on time 0% of the time in Aug 2025 – Jul 2026, worse than the 78% national average.
- 0% were cancelled, and 0% arrived an hour or more late.
- Republic Airways is the only airline reporting nonstop flights on this route.
- The largest source of delay minutes was air traffic control & airport congestion (100%).
Which airline is most on time from STL to IAD?
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 |
|---|---|---|---|---|---|
| Republic AirwaysRegional airline operating flights for American Eagle, Delta Connection and United Express. | 0% | 0.0% | 25 min | 0.0% | 1 |
Best time of day to fly
On-time arrival rate by scheduled departure hour (local time).
Not enough departures across different hours to compare.
Best day of the week
On-time arrival rate by day of departure.
- Tuesday0%0.0% cancelled
On-time trend by month
Monthly trend appears once two or more months of data are available.
Why flights are late
Share of delay minutes by cause, as reported by airlines to the DOT.
- Air traffic control & airport congestion100%
- Airline (crew, maintenance, cleaning, fueling)0%
- Late-arriving aircraft0%
- Extreme weather0%
- Security0%
Why flights are cancelled
Share of cancellations by reason.
No cancellation causes recorded in this period.
STL to IAD: common questions
- How often are STL to IAD flights on time?
- 0% 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 St. Louis to Washington cancelled?
- 0.0% of scheduled flights were cancelled (0 of 1).
- How long are typical delays?
- Across all flights the average arrival delay was 25 min (early arrivals count as zero). Flights that were late arrived 25 min behind schedule on average, and 0.0% of flights were an hour or more late.
- How long is taxi time at STL?
- Flights on this route spent 51 min taxiing from the gate to takeoff on average.
Related routes
Return trip: IAD to STL — 100% on time
More flights from St. Louis
Data: U.S. DOT Bureau of Transportation Statistics, Aug 2025 – Jul 2026 (12 months). Latest month published by BTS: July 2026. Route: STL → IAD, nonstop flights by US airlines that report to the DOT. How we calculate this.