Best Time to Fly SAT to IAD: On-Time Stats by Hour & Airline
San Antonio International → Washington Dulles International
Data through July 2026 · Last updated October 18, 2026
Over the last 12 months, 93.7% of San Antonio (SAT) to Washington (IAD) flights arrived on time (641 scheduled flights). That is 16.1 points above the national average of 77.6%.
United Airlines was the only reporting airline with regular flights on this route.
August has been the best month (96% on time) and Monday the weakest day of the week (89%).
0.6% of flights were cancelled, versus 1.8% nationally.
SAT to IAD on-time performance by airline
Last 12 months. Airlines with fewer than 30 completed flights are marked “limited data”.
| Airline | On time | Avg delay when late | Cancelled | Flights |
|---|---|---|---|---|
| United Airlines | 93.7% | 103 min | 0.6% | 641 |
80%+ good 70–79.9% fair <70% poor
Best time of day to fly SAT to IAD
On-time arrival % by scheduled departure hour (local time), 1,278 flights over 24 months.
Show the numbers
| Departure hour | On time | Cancelled | Flights |
|---|---|---|---|
| 7am–8am | 94.3% | 0.6% | 669 |
| 11am–12pm | 85.5% | 0.0% | 128 |
| 12pm–1pm | 88.8% | 0.8% | 480 |
| 4pm–5pm | Limited data | 1 | |
Best day of the week
24 months, by day of departure.
Best month to fly
24 months, by calendar month.
Holiday travel on SAT to IAD
On-time arrivals during holiday periods compared with all other days, last 24 months.
| Period | On time | vs other days | Cancelled | Flights |
|---|---|---|---|---|
| Thanksgiving week (Tue before to Mon after) | Limited data | 26 | ||
| Christmas & New Year (Dec 20 - Jan 3) | 90.6% | -1.0 pts | 0.0% | 53 |
| Summer peak (Jun 15 - Aug 15) | 90.1% | -1.5 pts | 0.9% | 226 |
| All other days | 91.6% | — | 0.6% | 973 |
Monthly on-time trend
On-time arrival % each month, with the 12-month US average for reference.
What causes delays on this route
Share of reported delay minutes, last 12 months (BTS cause categories).