IAD to SAT flight delays & on-time performance
Nonstop flights from Washington Dulles International Airport to San Antonio International Airport · 1,362 miles · Aug 2025 – Jul 2026
No FAA-reported ground stops or delays at IAD or SAT right now. Individual flights can still be delayed by the airline; check with your airline for your flight.
Key facts
- Flights from Washington (IAD) to San Antonio (SAT) arrived on time 86% of the time in Aug 2025 – Jul 2026, better than the 78% national average.
- 0.6% were cancelled, and 6% arrived an hour or more late.
- United Airlines is the only airline reporting nonstop flights on this route.
- Departures scheduled around 8am did best (94% on time); around 6pm did worst (80%).
- Monday was the most reliable day to fly (90% on time) and Sunday the least (79%).
- The largest source of delay minutes was airline (crew, maintenance, cleaning, fueling) (42%).
Which airline is most on time from IAD to SAT?
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 | 86% | 0.6% | 15 min | 6.3% | 641 |
Best time of day to fly
On-time arrival rate by scheduled departure hour (local time).
- 8am94%280 flights
- 5pm80%341 flights
- 6pm80%20 flights
Best day of the week
On-time arrival rate by day of departure.
- Monday90%0.0% cancelled
- Tuesday88%0.0% cancelled
- Wednesday88%0.0% cancelled
- Thursday87%1.0% cancelled
- Friday86%0.0% cancelled
- Saturday83%1.6% cancelled
- Sunday79%2.0% cancelled
On-time trend by month
Why flights are late
Share of delay minutes by cause, as reported by airlines to the DOT.
- Airline (crew, maintenance, cleaning, fueling)42%
- Late-arriving aircraft35%
- Air traffic control & airport congestion18%
- Extreme weather5%
- Security0%
Why flights are cancelled
Share of cancellations by reason.
- Extreme weather75%
- Airline (crew, maintenance, cleaning, fueling)25%
- Air traffic control & airport congestion0%
- Security0%
IAD to SAT: common questions
- How often are IAD to SAT flights on time?
- 86% 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 Washington to San Antonio cancelled?
- 0.6% of scheduled flights were cancelled (4 of 641).
- How long are typical delays?
- Across all flights the average arrival delay was 15 min (early arrivals count as zero). Flights that were late arrived 104 min behind schedule on average, and 6.3% of flights were an hour or more late.
- How long is taxi time at IAD?
- Flights on this route spent 22 min taxiing from the gate to takeoff on average.
Related routes
Return trip: SAT to IAD — 94% on time
More flights from Washington
Data: U.S. DOT Bureau of Transportation Statistics, Aug 2025 – Jul 2026 (12 months). Latest month published by BTS: July 2026. Route: IAD → SAT, nonstop flights by US airlines that report to the DOT. How we calculate this.