Best Time to Fly IAD to SFO: On-Time Stats by Hour & Airline
Washington Dulles International → San Francisco International
Data through July 2026 · Last updated October 18, 2026
2,729 flights were scheduled from Washington (IAD) to San Francisco (SFO) in the last 12 months, and 78.7% of those that flew arrived on time, 1.1 points above the US average of 77.6%.
Among 2 airlines, United Airlines led with 78.8% on time and Alaska Airlines was last with 76.3%.
Over 24 months, Tuesday was the most reliable day (85% on time) and June the worst month (68%).
The cancellation rate was 0.8% (US average 1.8%).
IAD to SFO 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 | 78.8% | 73 min | 0.8% | 2,691 |
| Alaska Airlines | 76.3% | 56 min | 0.0% | 38 |
80%+ good 70–79.9% fair <70% poor
Best time of day to fly IAD to SFO
On-time arrival % by scheduled departure hour (local time), 5,700 flights over 24 months.
Show the numbers
| Departure hour | On time | Cancelled | Flights |
|---|---|---|---|
| 6am–7am | 88.5% | 0.2% | 600 |
| 7am–8am | 92.1% | 1.0% | 192 |
| 8am–9am | 82.1% | 1.1% | 843 |
| 9am–10am | 85.7% | 0.6% | 169 |
| 12pm–1pm | 83.3% | 0.6% | 730 |
| 2pm–3pm | 84.0% | 0.4% | 521 |
| 3pm–4pm | 76.1% | 0.0% | 209 |
| 4pm–5pm | 83.9% | 0.7% | 458 |
| 5pm–6pm | 47.9% | 1.8% | 334 |
| 6pm–7pm | 69.5% | 1.5% | 597 |
| 7pm–8pm | 72.3% | 0.4% | 277 |
| 8pm–9pm | 51.9% | 0.0% | 79 |
| 9pm–10pm | Limited data | 5 | |
| 10pm–11pm | 83.1% | 0.3% | 686 |
Best day of the week
24 months, by day of departure.
Best month to fly
24 months, by calendar month.
Holiday travel on IAD to SFO
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) | 79.5% | -2.8 pts | 0.9% | 113 |
| Christmas & New Year (Dec 20 - Jan 3) | 65.5% | -16.8 pts | 0.0% | 249 |
| Summer peak (Jun 15 - Aug 15) | 70.5% | -11.7 pts | 0.8% | 998 |
| All other days | 82.2% | — | 0.7% | 4,340 |
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).