The sector is held by Alaska Airlines, Delta Air Lines and United Airlines.
Airport pair · hand carry reference
IAD Washington DC to SEA Seattle
Washington Dulles, the United States, to Seattle Tacoma International, the United States. Computed from the scheduled network held on 2026-09-07.
- Nonstop
- 6.9 times a day
- Great circle
- 3,702 km
- Block, estimated
- 4h 58m
- Door to door
- 11h 43m
What IAD to SEA looks like
The IAD to SEA sector, the carriers on it and the flying time, before anything is promised to anybody.
Washington DC IAD to Seattle SEA is a long haul sector of 3,702 km by great circle, flown nonstop 6.9 times a day.
At the cruise speed this site models for 3,702 km, 880 km an hour, and thirty minutes of taxi at the two ends, the flight blocks at about 4h 58m.
Washington DC IAD is a major hub in the network held here, 270 scheduled destinations and 481.8 departures a day. Seattle SEA has 145 destinations and 717.9 departures a day.
Seattle is 3 hours behind of Washington DC all year.
The pair sits inside the Americas, a corridor where the site already publishes 13 written lanes that go into customs and ground detail this page does not.
Who flies the sector, and how often
Average daily frequencies on IAD to SEA from the scheduled route statistics, both directions, with the operating carriers named.
| Direction | Flights a day | Flights a week | Operated by |
|---|---|---|---|
| IAD to SEA | 6.86 | 48 | Alaska Airlines, Delta Air Lines, United Airlines |
| SEA to IAD | 2.29 | 16 | United Airlines |
3 carriers are recorded on the sector, so a missed departure is normally a rebooking rather than a lost day.
The two directions are not level: IAD to SEA runs 6.9 times a day, the return runs about twice a day, and a round trip has to be planned around the thinner of the two.
At 6.9 times a day there is usually another departure within a few hours, which is what makes a same day booking on this pair realistic.
Between them the two directions put about 64 departures a week on IAD to SEA, which is the number that decides whether a seat can be found today or on Thursday.
The clock from collection to signature
The same ground timings the route calculator starts from, applied to the 4h 58m block time on IAD to SEA. Change any of them in the tool further down and the total moves with them.
| Stage | Allowed | Elapsed |
|---|---|---|
| Collection and the run to IAD | 90 min | 1h 30m |
| At IAD before departure | 180 min | 4h 30m |
| IAD to SEA in the air, estimated | 298 min | 9h 28m |
| Formalities at SEA | 90 min | 10h 58m |
| Delivery run in Seattle | 45 min | 11h 43m |
| Door to door | 703 min | 11h 43m |
On the desk standard ground timings, ninety minutes to collect and reach the airport, three hours at the airport before departure, ninety minutes of arrival formalities and a forty five minute delivery run, the door to door figure for IAD to SEA is 11h 43m.
A courier who leaves Washington DC at 09:00 local is on the ground in Seattle at about 10:58 local and at the door by 13:13 the same day.
Working backwards from a six in the evening handover in Seattle, the last useful departure from Washington DC is around 13:47 local.
When the nonstop does not work
Every airport that joins the two ends, ranked by when they land, among the ones whose weaker leg is dependable enough to plan on. Connection time is allowed for the size of the hub. 63 of them join IAD to SEA.
| Connecting at | IAD to hub, flights a day | Hub to SEA, flights a day | Track, km | Estimated, gate to gate |
|---|---|---|---|---|
| Washington DC DCA | 0.57 | 3.57 | 3,776 | 6h 48m |
| Cleveland CLE | 5.14 | 2.29 | 3,707 | 6h 50m |
| Columbus CMH | 7.29 | 2.29 | 3,717 | 6h 51m |
| Baltimore BWI | 0.71 | 3.43 | 3,821 | 6h 52m |
| Detroit DTW | 8.14 | 8.14 | 3,709 | 6h 53m |
| Kansas City MCI | 2.57 | 3.57 | 3,879 | 6h 57m |
With 6.9 times a day on the nonstop, a connection here is a disruption plan rather than a routing, and it is listed because a closed runway or a cancellation wave is exactly when nobody has time to work it out.
63 airports connect the two ends on the scheduled network held here. The quickest of the dependable ones is Washington DC DCA, where the weaker of the two legs still runs 4 times a week.
Through DCA the routing covers 3,776 km against the 3,702 km nonstop track and takes about 6h 48m in the air and on the ground at the hub, allowing 75 minutes to connect at an airport of that size.
That is only 1h 50m more than the nonstop, which is close enough that a connection is worth taking when the nonstop is full or badly timed.
Behind it, Cleveland CLE at 6h 50m and Columbus CMH at 6h 51m hold the same connection, so a booking has three hubs to try before it has to wait for the nonstop.
If nothing suitable leaves Washington DC, Washington DC DCA is 38 km away by great circle and carries 112 scheduled destinations of its own, which is usually a shorter road transfer than a lost day.
If nothing suitable leaves Seattle, Victoria YYJ is 157 km away by great circle and carries 22 scheduled destinations of its own, which is usually a shorter road transfer than a lost day.
Industry within reach of the two ends
Public manufacturing and research sites whose logistics run through IAD or SEA. Listed as industrial geography, not as customers of anyone.
- Boeing, Everett and RentonWidebody and 737 final assembly. A European supplier base and an American line, eight time zones apart. Logistics through Seattle SEA.
Plan Washington DC to Seattle yourself
The same tool the dispatchers use, open to anybody and free. It is loaded with this pair already. Change either end, add a stopover or a preferred airline, and it works out the connection, the transit and the door to door clock, with the real departures underneath. Put it on your own site if it is useful to you.
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Restrictions
Where this came from, and where to look next
- Carriers and frequencies: AeroDataBox scheduled route statistics, retrieved 2026-09-07. Average daily flights, not a timetable.
- Distances: great circle from published coordinates. They read short against a flown track, which is why the block time above applies a factor to them.
- Block and connection times: the same model the route calculator lower down this page runs, at the same rounding.
- Restrictions: the airport notes file, checked 2026-09-07.
- Industrial sites: public company information. Nothing here says or implies that any company named is a customer of any courier operator.
Who publishes this. OnBoard Courier is a placement desk in Dubai. An assignment is carried out by a vetted partner operator, with the desk as the single point of contact from the quote to the signature. This page exists because our own dispatchers need the answer for IAD to SEA in the twenty minutes before a promise is made, and a reference only one operator can read is not a reference. Free to read, quote and cite. Found an error? Tell us and we will correct it.
If you need something moved rather than looked up, the desk prices a hand carry in fifteen minutes.
- The IAD airport entry
- The SEA airport entry
- Hand carry into the United States
- The written lane, Dubai to Seattle
- The written lane, Seattle to Nagoya
- The route calculator
More pairs through IAD and SEA: Washington DC to Detroit, Boston to Washington DC, Houston to Washington DC, Dubai to Washington DC, Washington DC to San Diego, Sao Paulo to Washington DC, Washington DC to Montreal, Charlotte to Washington DC.