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3,702 km · Domestic

Washington Dulles (IAD) – Seattle–Tacoma (SEA)

In July 2026, 421 flights operated between Washington Dulles and Seattle–Tacoma (both directions), and 83.8% left on time, according to the US BTS.

Official · July 2026 according to the US BTS only airlines required to report on-time data to the US DOT

Flights per month

Only complete months are shown. A month appears once the source has published every day of it.

The most recent periods19 periods
PeriodFlights operated 2025Flights operated 2026Change vs last year
January204199▼ 2.5%
February187184▼ 1.6%
March2322320.0%
April310255▼ 17.7%
May404403▼ 0.2%
June474391▼ 17.5%
July487421▼ 13.6%
August441––
September358––
October307–in progress
November235––
December247––
Year to date (Jan–Jul)2,2982,085▼ 9.3%

On-time departures by month

Departures within 15 minutes of schedule.

The most recent periods19 periods
PeriodOn-time departures 2025On-time departures 2026Change vs last year
January80.4%82.9%▲ 3.1%
February76.5%87.5%▲ 14.4%
March82.8%75.0%▼ 9.4%
April86.8%83.5%▼ 3.8%
May82.2%86.1%▲ 4.7%
June76.4%82.6%▲ 8.1%
July75.4%83.8%▲ 11.1%
August81.0%––
September91.1%––
October83.7%–in progress
November79.1%––
December83.4%––
Year-to-date average (Jan–Jul)80.1%83.1%▲ 3.7%

Cancelled flights by month

The most recent periods19 periods
PeriodCancelled flights 2025Cancelled flights 2026Change vs last year
January36▲ 100.0%
February03–
March02–
April02–
May20▼ 100.0%
June65▼ 16.7%
July330.0%
August2––
September0––
October4–in progress
November3––
December1––
Year to date (Jan–Jul)1421▲ 50.0%

Airlines on this route

  1. Alaska Airlines 42.6%
  2. United Airlines 37.2%
  3. Delta Air Lines 20.2%

Oct 1, 2024 – Jul 31, 2026

By direction

IAD → SEA

Scheduled flights
3,446
Flights operated
3,420
Cancelled
26 · 0.8%
On-time departures
83.5%

SEA → IAD

Scheduled flights
3,448
Flights operated
3,428
Cancelled
20 · 0.6%
On-time departures
81.9%

IAD → SEA and SEA → IAD counted separately.

Airlines on this route

Oct 1, 2024 – Jul 31, 2026
AirlineScheduled flights Share On-time departures Cancelled
Alaska Airlines AS 2,934 42.6% 79.1% 17
United Airlines UA 2,564 37.2% 87.4% 18
Delta Air Lines DL 1,396 20.2% 81.7% 11

Shares are of scheduled flights in the period shown. Codeshare flights are counted once, under the operating airline.

Flight timing & delays

Historical departures, grouped by the scheduled local time at the departure airport. These are recorded outcomes, not a forecast for your flight.

Times are local to the departure airport of each flight; both directions are combined.

US domestic sectors recorded by BTS

Source: the US BTS · Oct 12, 2024 → Jul 31, 2026

Lowest average delay06:00–07:00-0.3min · 218 recorded · 217 measured
Gap to highest-delay hour17.5min06:00 ↔ 18:00
Recorded flights6,894IAD–SEA

Departure hour

On-time departures Partial coverage: only airlines that report on-time data to the US DOT
00:00 · No observations · 0 recorded · 0 measured · Source: the US BTS 01:00 · No observations · 0 recorded · 0 measured · Source: the US BTS 02:00 · No observations · 0 recorded · 0 measured · Source: the US BTS 03:00 · No observations · 0 recorded · 0 measured · Source: the US BTS 04:00 · No observations · 0 recorded · 0 measured · Source: the US BTS 05:00 · No observations · 0 recorded · 0 measured · Source: the US BTS 06:00 · 94.5% · 218 recorded · 217 measured · Source: the US BTS 07:00 · 86.1% · 1,027 recorded · 1,019 measured · Source: the US BTS 08:00 · 93.1% · 993 recorded · 990 measured · Source: the US BTS 09:00 · 82.8% · 768 recorded · 763 measured · Source: the US BTS 10:00 · Fewer than 200 measured departures · 190 recorded · 189 measured · Source: the US BTS 11:00 · Fewer than 200 measured departures · 5 recorded · 5 measured · Source: the US BTS 12:00 · Fewer than 200 measured departures · 194 recorded · 194 measured · Source: the US BTS 13:00 · 91.1% · 373 recorded · 372 measured · Source: the US BTS 14:00 · No observations · 0 recorded · 0 measured · Source: the US BTS 15:00 · 71.3% · 279 recorded · 275 measured · Source: the US BTS 16:00 · 78.1% · 425 recorded · 424 measured · Source: the US BTS 17:00 · 80.8% · 697 recorded · 693 measured · Source: the US BTS 18:00 · 70.1% · 454 recorded · 448 measured · Source: the US BTS 19:00 · Fewer than 200 measured departures · 114 recorded · 113 measured · Source: the US BTS 20:00 · No observations · 0 recorded · 0 measured · Source: the US BTS 21:00 · 74.0% · 316 recorded · 315 measured · Source: the US BTS 22:00 · 74.4% · 437 recorded · 433 measured · Source: the US BTS 23:00 · 79.2% · 404 recorded · 398 measured · Source: the US BTS

Hover, tap or focus a point to see its value, sample and source.

Average departure delay Partial coverage: only airlines that report on-time data to the US DOT
00:00 · No observations · 0 recorded · 0 measured · Source: the US BTS 01:00 · No observations · 0 recorded · 0 measured · Source: the US BTS 02:00 · No observations · 0 recorded · 0 measured · Source: the US BTS 03:00 · No observations · 0 recorded · 0 measured · Source: the US BTS 04:00 · No observations · 0 recorded · 0 measured · Source: the US BTS 05:00 · No observations · 0 recorded · 0 measured · Source: the US BTS 06:00 · -0.3 min · 218 recorded · 217 measured · Source: the US BTS 07:00 · 9.9 min · 1,027 recorded · 1,019 measured · Source: the US BTS 08:00 · 2.4 min · 993 recorded · 990 measured · Source: the US BTS 09:00 · 6.9 min · 768 recorded · 763 measured · Source: the US BTS 10:00 · Fewer than 200 measured departures · 190 recorded · 189 measured · Source: the US BTS 11:00 · Fewer than 200 measured departures · 5 recorded · 5 measured · Source: the US BTS 12:00 · Fewer than 200 measured departures · 194 recorded · 194 measured · Source: the US BTS 13:00 · 4.6 min · 373 recorded · 372 measured · Source: the US BTS 14:00 · No observations · 0 recorded · 0 measured · Source: the US BTS 15:00 · 16.9 min · 279 recorded · 275 measured · Source: the US BTS 16:00 · 13.8 min · 425 recorded · 424 measured · Source: the US BTS 17:00 · 13.7 min · 697 recorded · 693 measured · Source: the US BTS 18:00 · 17.2 min · 454 recorded · 448 measured · Source: the US BTS 19:00 · Fewer than 200 measured departures · 114 recorded · 113 measured · Source: the US BTS 20:00 · No observations · 0 recorded · 0 measured · Source: the US BTS 21:00 · 10.6 min · 316 recorded · 315 measured · Source: the US BTS 22:00 · 15.6 min · 437 recorded · 433 measured · Source: the US BTS 23:00 · 12.4 min · 404 recorded · 398 measured · Source: the US BTS

Hover, tap or focus a point to see its value, sample and source.

Recorded flights Partial coverage: only airlines that report on-time data to the US DOT
00:00 · No observations · 0 recorded · 0 measured · Source: the US BTS 01:00 · No observations · 0 recorded · 0 measured · Source: the US BTS 02:00 · No observations · 0 recorded · 0 measured · Source: the US BTS 03:00 · No observations · 0 recorded · 0 measured · Source: the US BTS 04:00 · No observations · 0 recorded · 0 measured · Source: the US BTS 05:00 · No observations · 0 recorded · 0 measured · Source: the US BTS 06:00 · 218 · 218 recorded · 217 measured · Source: the US BTS 07:00 · 1,027 · 1,027 recorded · 1,019 measured · Source: the US BTS 08:00 · 993 · 993 recorded · 990 measured · Source: the US BTS 09:00 · 768 · 768 recorded · 763 measured · Source: the US BTS 10:00 · 190 · 190 recorded · 189 measured · Source: the US BTS 11:00 · 5 · 5 recorded · 5 measured · Source: the US BTS 12:00 · 194 · 194 recorded · 194 measured · Source: the US BTS 13:00 · 373 · 373 recorded · 372 measured · Source: the US BTS 14:00 · No observations · 0 recorded · 0 measured · Source: the US BTS 15:00 · 279 · 279 recorded · 275 measured · Source: the US BTS 16:00 · 425 · 425 recorded · 424 measured · Source: the US BTS 17:00 · 697 · 697 recorded · 693 measured · Source: the US BTS 18:00 · 454 · 454 recorded · 448 measured · Source: the US BTS 19:00 · 114 · 114 recorded · 113 measured · Source: the US BTS 20:00 · No observations · 0 recorded · 0 measured · Source: the US BTS 21:00 · 316 · 316 recorded · 315 measured · Source: the US BTS 22:00 · 437 · 437 recorded · 433 measured · Source: the US BTS 23:00 · 404 · 404 recorded · 398 measured · Source: the US BTS

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View the figures
Departure hourOn-time departuresAverage departure delayWith departure timeRecorded flights
00:00No observations———
01:00No observations———
02:00No observations———
03:00No observations———
04:00No observations———
05:00No observations———
06:0094.5%-0.3 min217218
07:0086.1%9.9 min1,0191,027
08:0093.1%2.4 min990993
09:0082.8%6.9 min763768
10:00Fewer than 200 measured departures—189190
11:00Fewer than 200 measured departures—55
12:00Fewer than 200 measured departures—194194
13:0091.1%4.6 min372373
14:00No observations———
15:0071.3%16.9 min275279
16:0078.1%13.8 min424425
17:0080.8%13.7 min693697
18:0070.1%17.2 min448454
19:00Fewer than 200 measured departures—113114
20:00No observations———
21:0074.0%10.6 min315316
22:0074.4%15.6 min433437
23:0079.2%12.4 min398404

Day of week

On-time departures Partial coverage: only airlines that report on-time data to the US DOT
Monday · 82.3% · 1,025 recorded · 1,019 measured · Source: the US BTS Tuesday · 84.3% · 938 recorded · 934 measured · Source: the US BTS Wednesday · 85.2% · 949 recorded · 947 measured · Source: the US BTS Thursday · 84.3% · 1,017 recorded · 1,012 measured · Source: the US BTS Friday · 80.8% · 1,028 recorded · 1,023 measured · Source: the US BTS Saturday · 81.5% · 913 recorded · 904 measured · Source: the US BTS Sunday · 80.6% · 1,024 recorded · 1,009 measured · Source: the US BTS

Hover, tap or focus a point to see its value, sample and source.

Average departure delay Partial coverage: only airlines that report on-time data to the US DOT
Monday · 8.9 min · 1,025 recorded · 1,019 measured · Source: the US BTS Tuesday · 8.2 min · 938 recorded · 934 measured · Source: the US BTS Wednesday · 7.7 min · 949 recorded · 947 measured · Source: the US BTS Thursday · 9.7 min · 1,017 recorded · 1,012 measured · Source: the US BTS Friday · 9.2 min · 1,028 recorded · 1,023 measured · Source: the US BTS Saturday · 11.3 min · 913 recorded · 904 measured · Source: the US BTS Sunday · 11.8 min · 1,024 recorded · 1,009 measured · Source: the US BTS

Hover, tap or focus a point to see its value, sample and source.

Recorded flights Partial coverage: only airlines that report on-time data to the US DOT
Monday · 1,025 · 1,025 recorded · 1,019 measured · Source: the US BTS Tuesday · 938 · 938 recorded · 934 measured · Source: the US BTS Wednesday · 949 · 949 recorded · 947 measured · Source: the US BTS Thursday · 1,017 · 1,017 recorded · 1,012 measured · Source: the US BTS Friday · 1,028 · 1,028 recorded · 1,023 measured · Source: the US BTS Saturday · 913 · 913 recorded · 904 measured · Source: the US BTS Sunday · 1,024 · 1,024 recorded · 1,009 measured · Source: the US BTS

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View the figures
Day of weekOn-time departuresAverage departure delayWith departure timeRecorded flights
Monday82.3%8.9 min1,0191,025
Tuesday84.3%8.2 min934938
Wednesday85.2%7.7 min947949
Thursday84.3%9.7 min1,0121,017
Friday80.8%9.2 min1,0231,028
Saturday81.5%11.3 min904913
Sunday80.6%11.8 min1,0091,024

Month of year

Months combine the same calendar month across the years shown; this is a seasonal pattern, not a monthly time series.

On-time departures Partial coverage: only airlines that report on-time data to the US DOT
Jan · 81.6% · 412 recorded · 403 measured · Source: the US BTS Feb · 81.9% · 374 recorded · 371 measured · Source: the US BTS Mar · 78.9% · 466 recorded · 464 measured · Source: the US BTS Apr · 85.3% · 567 recorded · 565 measured · Source: the US BTS May · 84.1% · 809 recorded · 807 measured · Source: the US BTS Jun · 79.2% · 876 recorded · 865 measured · Source: the US BTS Jul · 79.3% · 914 recorded · 908 measured · Source: the US BTS Aug · 81.0% · 443 recorded · 441 measured · Source: the US BTS Sep · 91.1% · 358 recorded · 358 measured · Source: the US BTS Oct · 85.9% · 558 recorded · 554 measured · Source: the US BTS Nov · 86.2% · 599 recorded · 596 measured · Source: the US BTS Dec · 82.4% · 518 recorded · 516 measured · Source: the US BTS

Hover, tap or focus a point to see its value, sample and source.

Average departure delay Partial coverage: only airlines that report on-time data to the US DOT
Jan · 11.6 min · 412 recorded · 403 measured · Source: the US BTS Feb · 11.7 min · 374 recorded · 371 measured · Source: the US BTS Mar · 12.1 min · 466 recorded · 464 measured · Source: the US BTS Apr · 4.6 min · 567 recorded · 565 measured · Source: the US BTS May · 6.4 min · 809 recorded · 807 measured · Source: the US BTS Jun · 10.8 min · 876 recorded · 865 measured · Source: the US BTS Jul · 15.8 min · 914 recorded · 908 measured · Source: the US BTS Aug · 12.6 min · 443 recorded · 441 measured · Source: the US BTS Sep · 1.0 min · 358 recorded · 358 measured · Source: the US BTS Oct · 6.6 min · 558 recorded · 554 measured · Source: the US BTS Nov · 8.2 min · 599 recorded · 596 measured · Source: the US BTS Dec · 9.2 min · 518 recorded · 516 measured · Source: the US BTS

Hover, tap or focus a point to see its value, sample and source.

Recorded flights Partial coverage: only airlines that report on-time data to the US DOT
Jan · 412 · 412 recorded · 403 measured · Source: the US BTS Feb · 374 · 374 recorded · 371 measured · Source: the US BTS Mar · 466 · 466 recorded · 464 measured · Source: the US BTS Apr · 567 · 567 recorded · 565 measured · Source: the US BTS May · 809 · 809 recorded · 807 measured · Source: the US BTS Jun · 876 · 876 recorded · 865 measured · Source: the US BTS Jul · 914 · 914 recorded · 908 measured · Source: the US BTS Aug · 443 · 443 recorded · 441 measured · Source: the US BTS Sep · 358 · 358 recorded · 358 measured · Source: the US BTS Oct · 558 · 558 recorded · 554 measured · Source: the US BTS Nov · 599 · 599 recorded · 596 measured · Source: the US BTS Dec · 518 · 518 recorded · 516 measured · Source: the US BTS

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View the figures
Month of yearOn-time departuresAverage departure delayWith departure timeRecorded flights
Jan81.6%11.6 min403412
Feb81.9%11.7 min371374
Mar78.9%12.1 min464466
Apr85.3%4.6 min565567
May84.1%6.4 min807809
Jun79.2%10.8 min865876
Jul79.3%15.8 min908914
Aug81.0%12.6 min441443
Sep91.1%1.0 min358358
Oct85.9%6.6 min554558
Nov86.2%8.2 min596599
Dec82.4%9.2 min516518

Delay and on-time rates need at least 200 measured departures per bucket. Smaller samples remain visible in the flight-count chart. An empty slot means no observations, not zero flights.

Recorded outcomes

  • On time 82.1% 5,663
  • Delayed >15 min 17.2% 1,185
  • Cancelled 0.7% 46
  • Missing departure time 0.0% 0

All recorded flights with a known scheduled local time, counted once. Missing actual times are shown separately.

On time means departing no more than 15 minutes after schedule. Cancelled flights and flights missing departure times are excluded from the on-time rate and average delay.

Flight numbers on this route

45
45 of 45
Flight numbersBy direction DeparturesOn time
DL1015 IAD → SEA 549 85.5%
DL541 SEA → IAD 538 77.9%
AS351 IAD → SEA 505 86.7%
UA326 IAD → SEA 495 82.1%
AS406 SEA → IAD 400 77.4%
AS367 SEA → IAD 333 74.1%
AS348 SEA → IAD 293 71.2%
UA2275 SEA → IAD 212 90.1%
AS375 IAD → SEA 207 83.9%
AS737 SEA → IAD 206 81.0%
AS406 IAD → SEA 191 69.7%
UA2217 SEA → IAD 172 94.7%
DL508 SEA → IAD 160 84.4%
AS737 IAD → SEA 129 66.9%
AS409 IAD → SEA 113 74.8%
DL508 IAD → SEA 107 75.7%
UA2131 SEA → IAD 95 94.7%
UA1360 SEA → IAD 92 92.4%
UA1395 IAD → SEA 89 93.3%
UA2398 SEA → IAD 88 92.1%
UA2402 SEA → IAD 88 68.2%
AS499 IAD → SEA 86 90.6%
UA2101 IAD → SEA 82 95.1%
UA2019 SEA → IAD 76 71.1%
UA2241 IAD → SEA 72 87.5%
UA1964 IAD → SEA 71 95.8%
UA264 SEA → IAD 67 84.4%
AS308 IAD → SEA 61 88.5%
UA1366 IAD → SEA 61 98.4%
UA1914 IAD → SEA 60 98.3%
UA1873 SEA → IAD 54 86.8%
AS361 IAD → SEA 52 94.1%
UA716 IAD → SEA 52 60.8%
AS307 SEA → IAD 48 64.6%
AS416 IAD → SEA 44 86.4%
AS436 SEA → IAD 42 92.9%
UA1159 IAD → SEA 37 88.9%
UA2463 SEA → IAD 37 91.9%
UA2855 SEA → IAD 37 100.0%
UA684 SEA → IAD 37 97.3%
UA1734 IAD → SEA 35 88.2%
UA688 SEA → IAD 34 97.1%
UA1774 IAD → SEA 32 81.3%
UA2861 SEA → IAD 32 93.8%
UA2211 SEA → IAD 30 83.3%

Flight numbers are the codes sold on tickets. On shared flights one aircraft can carry several of them. Only numbers with at least 30 flights have a page.

Monthly figures
PeriodFlights operated Change vs last yearCancelled On-time departures
July 2026 421 −13.6% 3 83.8%
June 2026 391 −17.5% 5 82.6%
May 2026 403 −0.2% 0 86.1%
April 2026 255 −17.7% 2 83.5%
March 2026 232 +0.0% 2 75.0%
February 2026 184 −1.6% 3 87.5%
January 2026 199 −2.5% 6 82.9%
December 2025 247 −8.2% 1 83.4%
November 2025 235 −34.9% 3 79.1%
October 2025 307 +24.3% 4 83.7%
September 2025 358 0 91.1%
August 2025 441 2 81.0%
July 2025 487 3 75.4%
June 2025 474 6 76.4%
May 2025 404 2 82.2%
April 2025 310 0 86.8%
March 2025 232 0 82.8%
February 2025 187 0 76.5%
January 2025 204 3 80.4%
December 2024 269 1 81.4%
November 2024 361 0 90.9%
October 2024 247 0 88.7%

How to read this chart

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