Route profile
DCA→SEA
Flight reliability, delays and best times to fly from Washington to Seattle, 2,329 miles.
Right now
Aviation weather is not currently a factor.
Aviation weather is not currently a factor.
Route reliability
July 2023 – July 2026
Better than 55% of comparable major US routes (4,598 compared)
Calculated from 2,759 flights. How this is calculated
DCA → SEA arrives on time 79.0% of the time; the return trip, SEA → DCA, arrives on time 79.3% of the time.
DCA → SEA spends 33.1 minutes on the ground on a 2,329-mile trip: 21.2 minutes from pushback to wheels-up at DCA and 12.0 minutes from touchdown to gate at SEA.
Source: US DOT Bureau of Transportation Statistics · Data covering July 2023 – July 2026
When it goes wrong
July 2023 – July 2026
40 min late
against a median of 8 min early
Percentiles over 2,759 operations; cancelled and diverted flights are counted separately.
Will your connection be tight enough?
Layovers at SEA after arriving from DCA.
| Connection time | Chance of missing | Reads as |
|---|---|---|
| 30 min | 36% | Likely to miss |
| 45 min | 20% | High risk |
| 60 min | 13% | Some risk |
| 90 min | 6.6% | Some risk |
| 120 min | 3.9% | Low risk |
This is one leg of a connection. Gate changes and the next flight's own schedule matter too. And a connection can fail before delay is even the question — this route cancels 1.20% of the time and diverts 0.40% of the time, which a late arrival never shows up in.
Chance of missing is the share of 2,715 arrivals on this route that landed later than the connection time less 30 minutes to reach the next gate.
The worst tenth of arrivals on this route land at least 40 minutes late (90th-percentile gate arrival delay), over 2,759 operations.
Any other layover length: connection checker.
Why DCA → SEA runs late
July 2023 – July 2026
airspace and airport capacity, including weather-driven flow control
the inbound aircraft was late, so this flight started late
crew, maintenance, boarding and fueling, all within the carrier’s control
weather severe enough to stop this flight specifically
Share of the delay minutes US DOT attributed to each cause for DCA → SEA. Only delays of 15 minutes or more are attributed.
Airlines on this route
Carriers with at least 200 flights, by the airline that operated each one.
| Carrier | Flights | On time | Cancelled | Median delay | Severe |
|---|---|---|---|---|---|
| Alaska Airlines | 2,250 | 80.8% | 0.89% | -8 min | 5.4% |
| Delta Air Lines | 509 | 70.7% | 2.55% | -5 min | 13.1% |
Alaska Airlines flew 81.6% of the 2,759 flights listed. Delta Air Lines cancelled 2.55% of its flights here against 0.89% for Alaska Airlines.
Alaska Airlines arrived on time 10.1 percentage points more often than Delta Air Lines on this route.
Flights on this route
Flight numbers with at least 600 operations here and still on the schedule.
Weekly and seasonal patterns
By day of week
Saturday is historically the most reliable day and Thursday the least, a gap of 11.8 percentage points.
By month
- Jan: 75.7%
- Feb: 71.0%
- Mar: 75.4%
- Apr: 87.1%
- May: 83.5%
- Jun: 79.2%
- Jul: 70.6%
- Aug: 86.0%
- Sep: 86.2%
- Oct: 86.6%
- Nov: 78.6%
- Dec: 68.8%
December is historically the weakest month and April the strongest, a spread of 18.3 percentage points.
Reliability over time
July 2023 – July 2026
Over the most recent 12 months (2025-08 to 2026-07), on-time arrivals averaged 74.3% against 80.0% in the 12 months before — declining by 5.7 percentage points.
Data and methodology
Calculated by FlyerIntel from 2,759 DCA → SEA flight records from the US DOT Bureau of Transportation Statistics, covering July 2023 – July 2026. Late means 15 or more minutes past scheduled arrival; cancelled and diverted flights are left out of on-time rates.
Full methodology · Data sources · Report a problem
Related research: How Long a Layover Needs to Be · Two Airlines on One Route · Best Time of Day to Fly From Major US Airports
Analysis last recomputed