Best Time to Fly SEA to BWI: On-Time Stats by Hour & Airline
Seattle/Tacoma International → Baltimore/Washington International Thurgood Marshall
Data through July 2026 · Last updated October 18, 2026
719 flights were scheduled from Seattle (SEA) to Baltimore (BWI) in the last 12 months, and 80.2% of those that flew arrived on time, 2.6 points above the US average of 77.6%.
Among 2 airlines, Alaska Airlines led with 84.2% on time and Southwest Airlines was last with 60.8%.
Over 24 months, Saturday was the most reliable day (83% on time) and July the worst month (68%).
The cancellation rate was 0.4% (US average 1.8%).
SEA to BWI 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 |
|---|---|---|---|---|
| Alaska Airlines | 84.2% | 39 min | 0.5% | 599 |
| Southwest Airlines | 60.8% | 38 min | 0.0% | 120 |
80%+ good 70–79.9% fair <70% poor
Best time of day to fly SEA to BWI
On-time arrival % by scheduled departure hour (local time), 1,353 flights over 24 months.
Show the numbers
| Departure hour | On time | Cancelled | Flights |
|---|---|---|---|
| 8am–9am | Limited data | 1 | |
| 9am–10am | 80.7% | 0.2% | 423 |
| 10am–11am | 78.0% | 0.3% | 292 |
| 9pm–10pm | 76.8% | 0.0% | 483 |
| 10pm–11pm | 79.1% | 0.7% | 154 |
Best day of the week
24 months, by day of departure.
Best month to fly
24 months, by calendar month.
Holiday travel on SEA to BWI
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 | 26 | ||
| Christmas & New Year (Dec 20 - Jan 3) | 83.3% | +2.9 pts | 0.0% | 60 |
| Summer peak (Jun 15 - Aug 15) | 72.4% | -8.1 pts | 0.0% | 356 |
| All other days | 80.5% | — | 0.3% | 911 |
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).