Best Time to Fly ORD to IAD: On-Time Stats by Hour & Airline
Chicago O'Hare International → Washington Dulles International
Data through July 2026 · Last updated October 18, 2026
2,082 flights were scheduled from Chicago (ORD) to Washington (IAD) in the last 12 months, and 75.9% of those that flew arrived on time, 1.7 points below the US average of 77.6%.
United Airlines was the only reporting airline with regular flights on this route.
September has been the best month (85% on time) and Sunday the weakest day of the week (73%).
0.8% of flights were cancelled, versus 1.8% nationally.
ORD 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 | 75.9% | 76 min | 0.8% | 2,082 |
80%+ good 70–79.9% fair <70% poor
Best time of day to fly ORD to IAD
On-time arrival % by scheduled departure hour (local time), 3,940 flights over 24 months.
Show the numbers
| Departure hour | On time | Cancelled | Flights |
|---|---|---|---|
| 6am–7am | 100.0% | 1.4% | 72 |
| 7am–8am | 90.3% | 0.0% | 31 |
| 8am–9am | 87.4% | 0.6% | 717 |
| 9am–10am | Limited data | 1 | |
| 10am–11am | 84.1% | 0.0% | 126 |
| 11am–12pm | 90.5% | 0.0% | 210 |
| 12pm–1pm | 83.5% | 0.0% | 127 |
| 1pm–2pm | 77.1% | 1.0% | 603 |
| 2pm–3pm | 68.4% | 0.2% | 402 |
| 3pm–4pm | 83.2% | 1.0% | 193 |
| 4pm–5pm | 69.9% | 0.7% | 148 |
| 5pm–6pm | 55.2% | 1.4% | 286 |
| 6pm–7pm | 71.0% | 0.9% | 442 |
| 7pm–8pm | Limited data | 1 | |
| 8pm–9pm | Limited data | 3 | |
| 9pm–10pm | 70.8% | 1.1% | 568 |
| 10pm–11pm | Limited data | 6 | |
| 11pm–12am | Limited data | 4 | |
Best day of the week
24 months, by day of departure.
Best month to fly
24 months, by calendar month.
Holiday travel on ORD 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) | 63.2% | -15.6 pts | 4.2% | 71 |
| Christmas & New Year (Dec 20 - Jan 3) | 75.6% | -3.3 pts | 0.0% | 135 |
| Summer peak (Jun 15 - Aug 15) | 69.5% | -9.3 pts | 1.6% | 774 |
| All other days | 78.8% | — | 0.5% | 2,960 |
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).