Seattle (SEA) to Washington (DCA): On-Time Performance
Data through July 2026
Seattle (SEA) to Washington (DCA) effectively runs on two schedules. In May 2026, 91% of arrivals were on time; in February 2025 that fell to 43% — a 48-point seasonal swing. Across the full period the route averages 79% on-time against a national 78%.
- On-time
- 79%
- arrived <15 min late
- Avg delay
- 13 min
- completed flights
- Cancelled
- 1.3%
- Flights/day
- 3.0
- last 12 months
- Duration
- 5h 7m
- scheduled
- Distance
- 2,329 mi
Best airline from SEA to DCA
2 airlines flew this route regularly between 2024-07 and 2026-07.
| Airline | On-time | Avg delay | Cancelled | Flights |
|---|---|---|---|---|
| Delta Air Linesmost reliable | 91% | 9 min | 2.4% | 509 |
| Alaska Airlines | 74% | 14 min | 0.9% | 1,519 |
Monthly on-time trend
Best time to fly from SEA to DCA
Aim for departures around 7 a.m. (91% on-time); avoid 2 p.m. departures (67%).
By day of week
| Day | On-time | Avg delay |
|---|---|---|
| Monday | 73% | 13 min |
| Tuesday | 81% | 11 min |
| Wednesday | 81% | 12 min |
| Thursday | 72% | 23 min |
| Friday | 78% | 12 min |
| Saturdaybest | 88% | 6 min |
| Sunday | 78% | 13 min |
What causes delays on this route
Share of total delay minutes by cause, as reported by carriers to the US DOT.
- Late-arriving aircraft12%
- Airline operations29%
- National airspace system53%
- Weather5%
Frequently asked questions
- How often are flights from SEA to DCA delayed?
- 21% of SEA–DCA flights arrived 15 or more minutes late (the US DOT definition of a delay) between 2024-07 and 2026-07. The average arrival delay across completed flights was 13 minutes.
- Which airline is most reliable from SEA to DCA?
- Delta Air Lines has the best on-time record on this route at 91%, based on 509 flights. 2 airlines flew SEA–DCA frequently enough to compare in this period.
- What is the best time of day to fly from SEA to DCA?
- Departures around 7 a.m. have the best record (91% on-time), while departures around 2 p.m. have the worst (67%). As on most US routes, delays accumulate through the day, so earlier flights are generally safer.
- How long is the flight from SEA to DCA?
- The scheduled SEA–DCA flight time averages 5h 7m over 2,329 miles. Actual arrival times vary — flights on this route land 15+ minutes late 21% of the time.
- How often are SEA to DCA flights cancelled?
- 1.3% of scheduled flights on this route were cancelled between 2024-07 and 2026-07, at or below the national rate of 1.6%.
- What is the worst month to fly from SEA to DCA?
- February 2025 was the roughest month in this dataset, with only 43% of arrivals on time. The best was May 2026 at 91%. If your dates are flexible, that 48-point gap is worth planning around.
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Based on 2,028 flights, 2024-07–2026-07. Source: US DOT Bureau of Transportation Statistics. Updated 2026-09-28.