Best Time to Fly PHX to IAD: On-Time Stats by Hour & Airline
Phoenix Sky Harbor International → Washington Dulles International
Data through July 2026 · Last updated October 18, 2026
Over the last 12 months, 85.6% of Phoenix (PHX) to Washington (IAD) flights arrived on time (1,037 scheduled flights). That is 8.0 points above the national average of 77.6%.
Among 2 airlines, United Airlines led with 90.6% on time and Southwest Airlines was last with 73.9%.
Over 24 months, Saturday was the most reliable day (88% on time) and July the worst month (74%).
The cancellation rate was 0.7% (US average 1.8%).
PHX 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 | 90.6% | 71 min | 0.8% | 731 |
| Southwest Airlines | 73.9% | 38 min | 0.3% | 306 |
80%+ good 70–79.9% fair <70% poor
Best time of day to fly PHX to IAD
On-time arrival % by scheduled departure hour (local time), 2,278 flights over 24 months.
Show the numbers
| Departure hour | On time | Cancelled | Flights |
|---|---|---|---|
| 12am–1am | Limited data | 5 | |
| 7am–8am | 92.6% | 0.0% | 82 |
| 8am–9am | 81.4% | 0.4% | 558 |
| 9am–10am | 88.6% | 0.0% | 372 |
| 10am–11am | 78.9% | 0.0% | 176 |
| 11am–12pm | 82.0% | 0.6% | 164 |
| 12pm–1pm | Limited data | 29 | |
| 1pm–2pm | 88.0% | 0.0% | 168 |
| 2pm–3pm | 84.7% | 0.0% | 111 |
| 3pm–4pm | 91.3% | 0.5% | 208 |
| 10pm–11pm | Limited data | 12 | |
| 11pm–12am | 90.1% | 1.8% | 393 |
Best day of the week
24 months, by day of departure.
Best month to fly
24 months, by calendar month.
Holiday travel on PHX 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) | 98.0% | +11.6 pts | 0.0% | 51 |
| Christmas & New Year (Dec 20 - Jan 3) | 84.2% | -2.3 pts | 0.0% | 120 |
| Summer peak (Jun 15 - Aug 15) | 78.1% | -8.3 pts | 1.1% | 277 |
| All other days | 86.5% | — | 0.4% | 1,830 |
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).