Washington (IAD) to San Antonio (SAT): On-Time Performance
Data through May 2026
The calendar drives reliability on IAD–SAT. October 2025 flights landed on schedule 98% of the time, but July 2025 dropped to 69% — a gap of 29 points. Across the full period the route averages 84% on-time against a national 78%. Morning departures also hold up better than evening ones (93% vs 77%), which matters most in the rough months.
- On-time
- 84%
- arrived <15 min late
- Avg delay
- 14 min
- completed flights
- Cancelled
- 0.6%
- Flights/day
- 1.7
- last 12 months
- Duration
- 3h 44m
- scheduled
- Distance
- 1,362 mi
Monthly on-time trend
Best time to fly from IAD to SAT
By day of week
| Day | On-time | Avg delay |
|---|---|---|
| Monday | 88% | 8 min |
| Tuesdaybest | 89% | 8 min |
| Wednesday | 82% | 13 min |
| Thursday | 83% | 17 min |
| Friday | 85% | 13 min |
| Saturday | 76% | 25 min |
| Sunday | 79% | 16 min |
What causes delays on this route
Share of total delay minutes by cause, as reported by carriers to the US DOT.
- Late-arriving aircraft31%
- Airline operations34%
- National airspace system20%
- Weather15%
Frequently asked questions
- How often are flights from IAD to SAT delayed?
- 16% of IAD–SAT flights arrived 15 or more minutes late (the US DOT definition of a delay) between 2024-06 and 2026-05. The average arrival delay across completed flights was 14 minutes.
- How long is the flight from IAD to SAT?
- The scheduled IAD–SAT flight time averages 3h 44m over 1,362 miles. Actual arrival times vary — flights on this route land 15+ minutes late 16% of the time.
- How often are IAD to SAT flights cancelled?
- 0.6% of scheduled flights on this route were cancelled between 2024-06 and 2026-05, at or below the national rate of 1.6%.
- What is the worst month to fly from IAD to SAT?
- July 2025 was the roughest month in this dataset, with only 69% of arrivals on time. The best was October 2025 at 98%. If your dates are flexible, that 29-point gap is worth planning around.
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Based on 1,276 flights, 2024-06–2026-05. Source: US DOT Bureau of Transportation Statistics. Updated 2026-07-01.