Route profile
SEA→DCA
Flight reliability, delays and best times to fly from Seattle to Washington, 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 69% of comparable major US routes (4,598 compared)
Calculated from 2,759 flights. How this is calculated · What counts as on time
SEA → DCA arrives on time 79.3% of the time; the return trip, DCA → SEA, arrives on time 79.0% of the time.
SEA → DCA spends 30.2 minutes on the ground on a 2,329-mile trip: 23.2 minutes from pushback to wheels-up at SEA and 7.0 minutes from touchdown to gate at DCA.
Source: US DOT Bureau of Transportation Statistics · Data covering July 2023 – July 2026
What stands out
Which day you fly matters unusually much here, a wider weekday spread than 93% of 4,467 comparable routes.
88.3% on time on a typical Saturday, against 73.9% on a Monday.
Source: FlyerIntel analysis of US DOT BTS data · July 2023 – July 2026 · Ranked against every other route with the same kind of figure and at least 4,467 in the comparison.
What sets this route apart
Where SEA to DCA differs most from similar routes by hour, weekday, month and airline, July 2023 – July 2026.
SEA to DCA struggles most at 1 PM: 69.3% of its flights scheduled then arrive on time, 6.4 points behind the 75.7% on routes of similar length at the same hour. Against all other routes the gap is 7.8 points.
SEA to DCA is at its best against routes of similar length for flights scheduled at 7 AM: 91.7% arrive on time, 6 points ahead of the 85.7% those routes manage at that hour. Against all other routes the gap is 3.9 points.
SEA to DCA holds up on Saturdays better than routes of similar length do: 88.3% on time to their 78.9%, a 9.4 points lead. Against all other routes the gap is 9.2 points.
In September, SEA to DCA runs 11.2 points below routes of similar length, 71.3% on time to 82.5%. Against all other routes the gap is 11.1 points.
June is kinder to SEA to DCA than to routes of similar length: 80.7% on time against 74.4%, 6.3 points better. Against all other routes the gap is 8 points.
SEA to DCA against comparable routes
July 2023 – July 2026| Measure | This route | Compared with | Them | Gap | Flights behind it |
|---|---|---|---|---|---|
| Hour: 1 PM departures | 69.3% | routes of similar length | 75.7% | −6.4 pts | 713 here, 55,818 there |
| Hour: 7 AM departures | 91.7% | routes of similar length | 85.7% | +6.0 pts | 494 here, 111,780 there |
| Weekday: Saturday | 88.3% | routes of similar length | 78.9% | +9.4 pts | 384 here, 152,398 there |
| Month: September | 71.3% | routes of similar length | 82.5% | −11.2 pts | 209 here, 89,282 there |
| Month: June | 80.7% | routes of similar length | 74.4% | +6.3 pts | 233 here, 98,801 there |
Each comparison pools the flights of other routes, with this route’s own left out. Similar length means within 15% of this route’s 2,329 miles, with at least 5 such routes. A bucket is set against the most comparable group that has enough flights: similar length, then the same origin (at least 3 routes), then all other routes. Hours, weekdays and months appear only where both sides have 120 completed flights, and airlines where both have 600. The gap must be at least 2 points and 2 standard errors, and only the largest gap each way is kept per measure. These are differences in the flights counted, not causes.
When it goes wrong
July 2023 – July 2026
39 min late
against a median of 7 min early
Percentiles over 2,759 operations; cancelled and diverted flights are counted separately.
Will your connection be tight enough?
Layovers at DCA after arriving from SEA.
| Connection time | Chance of missing | Reads as |
|---|---|---|
| 30 min | 36% | Likely to miss |
| 45 min | 20% | High risk |
| 60 min | 12% | Some risk |
| 90 min | 5.5% | Some risk |
| 120 min | 2.8% | 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 0.98% of the time and diverts 1.01% of the time, which a late arrival never shows up in.
Chance of missing is the share of 2,704 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 39 minutes late (90th-percentile gate arrival delay), over 2,759 operations.
Any other layover length: connection checker.
Why SEA → DCA runs late
July 2023 – July 2026
airspace and airport capacity, including weather-driven flow control
crew, maintenance, boarding and fueling, all within the carrier’s control
the inbound aircraft was late, so this flight started late
weather severe enough to stop this flight specifically
screening or terminal security incidents
Share of the delay minutes US DOT attributed to each cause for SEA → DCA. Only delays of 15 minutes or more are attributed. What the five causes mean
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 | 76.5% | 0.67% | -5 min | 6.3% |
| Delta Air Lines | 509 | 91.7% | 2.36% | -13 min | 2.8% |
Alaska Airlines flew 81.6% of the 2,759 flights listed. Delta Air Lines cancelled 2.36% of its flights here against 0.67% for Alaska Airlines.
Delta Air Lines arrived on time 15.2 percentage points more often than Alaska Airlines 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 Monday the least, a gap of 14.4 percentage points.
By month
- Jan: 80.3%
- Feb: 70.3%
- Mar: 82.1%
- Apr: 83.8%
- May: 81.7%
- Jun: 80.7%
- Jul: 72.2%
- Aug: 77.9%
- Sep: 71.3%
- Oct: 85.3%
- Nov: 83.7%
- Dec: 82.7%
February is historically the weakest month and October the strongest, a spread of 15.0 percentage points.
Reliability over time
July 2023 – July 2026
Over the most recent 12 months (2025-08 to 2026-07), on-time arrivals averaged 82.1% against 76.7% in the 12 months before — improving by 5.4 percentage points.
Data and methodology
Calculated by FlyerIntel from 2,759 SEA → DCA 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