Best Time to Fly IAD to PHL: On-Time Stats by Hour & Airline
Washington Dulles International → Philadelphia International
Data through July 2026 · Last updated October 18, 2026
Over the last 12 months, 81.8% of Washington (IAD) to Philadelphia (PHL) flights arrived on time (212 scheduled flights). That is 4.1 points above the national average of 77.6%.
Republic Airways was the only reporting airline with regular flights on this route.
June has been the best month (91% on time) and Monday the weakest day of the week (76%).
4.2% of flights were cancelled, versus 1.8% nationally.
IAD to PHL 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 |
|---|---|---|---|---|
| Republic Airways | 81.8% | 68 min | 4.2% | 212 |
80%+ good 70–79.9% fair <70% poor
Best time of day to fly IAD to PHL
On-time arrival % by scheduled departure hour (local time), 217 flights over 24 months.
Show the numbers
| Departure hour | On time | Cancelled | Flights |
|---|---|---|---|
| 8am–9am | 83.3% | 4.3% | 69 |
| 10am–11am | Limited data | 1 | |
| 12pm–1pm | 86.5% | 0.0% | 37 |
| 2pm–3pm | Limited data | 1 | |
| 5pm–6pm | 74.3% | 5.4% | 37 |
| 10pm–11pm | 80.9% | 5.6% | 72 |
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 PHL
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 | 11 | ||
| Christmas & New Year (Dec 20 - Jan 3) | Limited data | 12 | ||
| Summer peak (Jun 15 - Aug 15) | 80.3% | -3.2 pts | 2.6% | 78 |
| All other days | 83.5% | — | 6.0% | 116 |
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).