Best Time to Fly ORD to SEA: On-Time Stats by Hour & Airline
Chicago O'Hare International → Seattle/Tacoma International
Data through July 2026 · Last updated October 18, 2026
Over the last 12 months, 68.2% of Chicago (ORD) to Seattle (SEA) flights arrived on time (5,558 scheduled flights). That is 9.4 points below the national average of 77.6%.
United Airlines was the most punctual of the 4 airlines on the route at 74.9%, while American Airlines trailed at 63.3%.
September has been the best month (84% on time) and Friday the weakest day of the week (69%).
1.5% of flights were cancelled, versus 1.8% nationally.
ORD to SEA 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 | 74.9% | 58 min | 0.7% | 1,504 |
| Delta Air Lines | 67.1% | 69 min | 1.4% | 907 |
| Alaska Airlines | 67.0% | 64 min | 1.9% | 1,796 |
| American Airlines | 63.3% | 68 min | 1.9% | 1,351 |
80%+ good 70–79.9% fair <70% poor
Best time of day to fly ORD to SEA
On-time arrival % by scheduled departure hour (local time), 10,781 flights over 24 months.
Show the numbers
| Departure hour | On time | Cancelled | Flights |
|---|---|---|---|
| 6am–7am | 84.8% | 1.0% | 837 |
| 7am–8am | 82.4% | 0.9% | 1,263 |
| 8am–9am | 74.4% | 0.3% | 870 |
| 9am–10am | 80.7% | 0.0% | 661 |
| 10am–11am | 74.7% | 1.0% | 622 |
| 11am–12pm | 70.5% | 1.2% | 327 |
| 12pm–1pm | 75.9% | 0.0% | 193 |
| 1pm–2pm | 84.8% | 0.4% | 913 |
| 2pm–3pm | 73.4% | 0.5% | 605 |
| 3pm–4pm | 70.8% | 0.9% | 578 |
| 4pm–5pm | 75.6% | 0.2% | 615 |
| 5pm–6pm | 57.0% | 1.7% | 845 |
| 6pm–7pm | 62.7% | 2.2% | 555 |
| 7pm–8pm | 62.2% | 0.3% | 863 |
| 8pm–9pm | 57.5% | 3.3% | 673 |
| 9pm–10pm | 51.2% | 2.7% | 257 |
| 10pm–11pm | 46.9% | 3.9% | 102 |
| 11pm–12am | Limited data | 2 | |
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 SEA
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) | 59.5% | -15.6 pts | 7.2% | 181 |
| Christmas & New Year (Dec 20 - Jan 3) | 68.2% | -7.0 pts | 0.6% | 363 |
| Summer peak (Jun 15 - Aug 15) | 65.2% | -9.9 pts | 1.1% | 2,446 |
| All other days | 75.1% | — | 0.9% | 7,791 |
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).