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4,006 km · Domestic

Boston Logan (BOS) – Seattle–Tacoma (SEA)

In July 2026, 618 flights operated between Boston Logan and Seattle–Tacoma (both directions), and 68.1% 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
January300247▼ 17.7%
February280242▼ 13.6%
March381343▼ 10.0%
April390342▼ 12.3%
May451506▲ 12.2%
June507551▲ 8.7%
July538618▲ 14.9%
August541––
September458––
October451–in progress
November325––
December317––
Year to date (Jan–Jul)2,8472,849▲ 0.1%

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
January85.3%79.4%▼ 6.9%
February80.0%85.5%▲ 6.9%
March84.0%78.7%▼ 6.3%
April85.9%79.5%▼ 7.5%
May78.5%83.8%▲ 6.8%
June71.8%72.2%▲ 0.6%
July68.2%68.1%▼ 0.1%
August77.4%––
September76.4%––
October76.1%–in progress
November85.2%––
December80.4%––
Year-to-date average (Jan–Jul)79.1%78.2%▼ 1.2%

Cancelled flights by month

The most recent periods19 periods
PeriodCancelled flights 2025Cancelled flights 2026Change vs last year
January113▲ 1,200.0%
February1115▲ 36.4%
March21▼ 50.0%
April12▲ 100.0%
May42▼ 50.0%
June35▲ 66.7%
July1016▲ 60.0%
August0––
September0––
October4–in progress
November2––
December5––
Year to date (Jan–Jul)3254▲ 68.8%

Airlines on this route

  1. Alaska Airlines 47.1%
  2. Delta Air Lines 39.7%
  3. JetBlue Airways 13.2%

Oct 1, 2024 – Jul 31, 2026

By direction

BOS → SEA

Scheduled flights
4,460
Flights operated
4,412
Cancelled
48 · 1.1%
On-time departures
80.8%

SEA → BOS

Scheduled flights
4,457
Flights operated
4,408
Cancelled
49 · 1.1%
On-time departures
76.0%

BOS → SEA and SEA → BOS counted separately.

Airlines on this route

Oct 1, 2024 – Jul 31, 2026
AirlineScheduled flights Share On-time departures Cancelled
Alaska Airlines AS 4,201 47.1% 78.4% 35
Delta Air Lines DL 3,536 39.7% 82.5% 44
JetBlue Airways B6 1,180 13.2% 66.4% 18

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 delay07:00–08:003.9min · 2,368 recorded · 2,342 measured
Gap to highest-delay hour17.8min07:00 ↔ 11:00
Recorded flights8,917BOS–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 · Fewer than 200 measured departures · 61 recorded · 61 measured · Source: the US BTS 07:00 · 89.2% · 2,368 recorded · 2,342 measured · Source: the US BTS 08:00 · 78.6% · 406 recorded · 402 measured · Source: the US BTS 09:00 · 82.5% · 626 recorded · 622 measured · Source: the US BTS 10:00 · 67.8% · 350 recorded · 348 measured · Source: the US BTS 11:00 · 72.2% · 742 recorded · 736 measured · Source: the US BTS 12:00 · Fewer than 200 measured departures · 6 recorded · 6 measured · Source: the US BTS 13:00 · Fewer than 200 measured departures · 53 recorded · 53 measured · Source: the US BTS 14:00 · No observations · 0 recorded · 0 measured · Source: the US BTS 15:00 · 72.1% · 1,049 recorded · 1,040 measured · Source: the US BTS 16:00 · 77.5% · 316 recorded · 311 measured · Source: the US BTS 17:00 · 80.9% · 281 recorded · 278 measured · Source: the US BTS 18:00 · 70.6% · 902 recorded · 888 measured · Source: the US BTS 19:00 · 68.4% · 394 recorded · 386 measured · Source: the US BTS 20:00 · Fewer than 200 measured departures · 1 recorded · 1 measured · Source: the US BTS 21:00 · Fewer than 200 measured departures · 141 recorded · 141 measured · Source: the US BTS 22:00 · 79.7% · 546 recorded · 538 measured · Source: the US BTS 23:00 · 77.1% · 675 recorded · 667 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 · Fewer than 200 measured departures · 61 recorded · 61 measured · Source: the US BTS 07:00 · 3.9 min · 2,368 recorded · 2,342 measured · Source: the US BTS 08:00 · 11.5 min · 406 recorded · 402 measured · Source: the US BTS 09:00 · 10.1 min · 626 recorded · 622 measured · Source: the US BTS 10:00 · 18.2 min · 350 recorded · 348 measured · Source: the US BTS 11:00 · 21.7 min · 742 recorded · 736 measured · Source: the US BTS 12:00 · Fewer than 200 measured departures · 6 recorded · 6 measured · Source: the US BTS 13:00 · Fewer than 200 measured departures · 53 recorded · 53 measured · Source: the US BTS 14:00 · No observations · 0 recorded · 0 measured · Source: the US BTS 15:00 · 17.0 min · 1,049 recorded · 1,040 measured · Source: the US BTS 16:00 · 11.5 min · 316 recorded · 311 measured · Source: the US BTS 17:00 · 7.1 min · 281 recorded · 278 measured · Source: the US BTS 18:00 · 18.2 min · 902 recorded · 888 measured · Source: the US BTS 19:00 · 19.9 min · 394 recorded · 386 measured · Source: the US BTS 20:00 · Fewer than 200 measured departures · 1 recorded · 1 measured · Source: the US BTS 21:00 · Fewer than 200 measured departures · 141 recorded · 141 measured · Source: the US BTS 22:00 · 9.3 min · 546 recorded · 538 measured · Source: the US BTS 23:00 · 14.0 min · 675 recorded · 667 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 · 61 · 61 recorded · 61 measured · Source: the US BTS 07:00 · 2,368 · 2,368 recorded · 2,342 measured · Source: the US BTS 08:00 · 406 · 406 recorded · 402 measured · Source: the US BTS 09:00 · 626 · 626 recorded · 622 measured · Source: the US BTS 10:00 · 350 · 350 recorded · 348 measured · Source: the US BTS 11:00 · 742 · 742 recorded · 736 measured · Source: the US BTS 12:00 · 6 · 6 recorded · 6 measured · Source: the US BTS 13:00 · 53 · 53 recorded · 53 measured · Source: the US BTS 14:00 · No observations · 0 recorded · 0 measured · Source: the US BTS 15:00 · 1,049 · 1,049 recorded · 1,040 measured · Source: the US BTS 16:00 · 316 · 316 recorded · 311 measured · Source: the US BTS 17:00 · 281 · 281 recorded · 278 measured · Source: the US BTS 18:00 · 902 · 902 recorded · 888 measured · Source: the US BTS 19:00 · 394 · 394 recorded · 386 measured · Source: the US BTS 20:00 · 1 · 1 recorded · 1 measured · Source: the US BTS 21:00 · 141 · 141 recorded · 141 measured · Source: the US BTS 22:00 · 546 · 546 recorded · 538 measured · Source: the US BTS 23:00 · 675 · 675 recorded · 667 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———
06:00Fewer than 200 measured departures—6161
07:0089.2%3.9 min2,3422,368
08:0078.6%11.5 min402406
09:0082.5%10.1 min622626
10:0067.8%18.2 min348350
11:0072.2%21.7 min736742
12:00Fewer than 200 measured departures—66
13:00Fewer than 200 measured departures—5353
14:00No observations———
15:0072.1%17.0 min1,0401,049
16:0077.5%11.5 min311316
17:0080.9%7.1 min278281
18:0070.6%18.2 min888902
19:0068.4%19.9 min386394
20:00Fewer than 200 measured departures—11
21:00Fewer than 200 measured departures—141141
22:0079.7%9.3 min538546
23:0077.1%14.0 min667675

Day of week

On-time departures Partial coverage: only airlines that report on-time data to the US DOT
Monday · 77.7% · 1,321 recorded · 1,304 measured · Source: the US BTS Tuesday · 80.2% · 1,222 recorded · 1,210 measured · Source: the US BTS Wednesday · 81.0% · 1,253 recorded · 1,246 measured · Source: the US BTS Thursday · 76.6% · 1,317 recorded · 1,301 measured · Source: the US BTS Friday · 78.3% · 1,325 recorded · 1,316 measured · Source: the US BTS Saturday · 78.2% · 1,161 recorded · 1,149 measured · Source: the US BTS Sunday · 77.3% · 1,318 recorded · 1,294 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 · 13.5 min · 1,321 recorded · 1,304 measured · Source: the US BTS Tuesday · 12.1 min · 1,222 recorded · 1,210 measured · Source: the US BTS Wednesday · 10.8 min · 1,253 recorded · 1,246 measured · Source: the US BTS Thursday · 15.0 min · 1,317 recorded · 1,301 measured · Source: the US BTS Friday · 11.6 min · 1,325 recorded · 1,316 measured · Source: the US BTS Saturday · 12.8 min · 1,161 recorded · 1,149 measured · Source: the US BTS Sunday · 14.5 min · 1,318 recorded · 1,294 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 · 1,321 · 1,321 recorded · 1,304 measured · Source: the US BTS Tuesday · 1,222 · 1,222 recorded · 1,210 measured · Source: the US BTS Wednesday · 1,253 · 1,253 recorded · 1,246 measured · Source: the US BTS Thursday · 1,317 · 1,317 recorded · 1,301 measured · Source: the US BTS Friday · 1,325 · 1,325 recorded · 1,316 measured · Source: the US BTS Saturday · 1,161 · 1,161 recorded · 1,149 measured · Source: the US BTS Sunday · 1,318 · 1,318 recorded · 1,294 measured · Source: the US BTS

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View the figures
Day of weekOn-time departuresAverage departure delayWith departure timeRecorded flights
Monday77.7%13.5 min1,3041,321
Tuesday80.2%12.1 min1,2101,222
Wednesday81.0%10.8 min1,2461,253
Thursday76.6%15.0 min1,3011,317
Friday78.3%11.6 min1,3161,325
Saturday78.2%12.8 min1,1491,161
Sunday77.3%14.5 min1,2941,318

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 · 82.6% · 561 recorded · 547 measured · Source: the US BTS Feb · 82.6% · 548 recorded · 522 measured · Source: the US BTS Mar · 81.5% · 727 recorded · 724 measured · Source: the US BTS Apr · 82.9% · 735 recorded · 732 measured · Source: the US BTS May · 81.3% · 963 recorded · 957 measured · Source: the US BTS Jun · 72.0% · 1,066 recorded · 1,058 measured · Source: the US BTS Jul · 68.2% · 1,182 recorded · 1,156 measured · Source: the US BTS Aug · 77.5% · 541 recorded · 541 measured · Source: the US BTS Sep · 76.4% · 458 recorded · 458 measured · Source: the US BTS Oct · 80.1% · 743 recorded · 739 measured · Source: the US BTS Nov · 86.5% · 700 recorded · 698 measured · Source: the US BTS Dec · 79.2% · 693 recorded · 688 measured · Source: the US BTS

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Average departure delay Partial coverage: only airlines that report on-time data to the US DOT
Jan · 8.2 min · 561 recorded · 547 measured · Source: the US BTS Feb · 15.5 min · 548 recorded · 522 measured · Source: the US BTS Mar · 7.9 min · 727 recorded · 724 measured · Source: the US BTS Apr · 8.1 min · 735 recorded · 732 measured · Source: the US BTS May · 7.9 min · 963 recorded · 957 measured · Source: the US BTS Jun · 16.7 min · 1,066 recorded · 1,058 measured · Source: the US BTS Jul · 27.1 min · 1,182 recorded · 1,156 measured · Source: the US BTS Aug · 13.2 min · 541 recorded · 541 measured · Source: the US BTS Sep · 16.0 min · 458 recorded · 458 measured · Source: the US BTS Oct · 11.4 min · 743 recorded · 739 measured · Source: the US BTS Nov · 4.4 min · 700 recorded · 698 measured · Source: the US BTS Dec · 10.5 min · 693 recorded · 688 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 · 561 · 561 recorded · 547 measured · Source: the US BTS Feb · 548 · 548 recorded · 522 measured · Source: the US BTS Mar · 727 · 727 recorded · 724 measured · Source: the US BTS Apr · 735 · 735 recorded · 732 measured · Source: the US BTS May · 963 · 963 recorded · 957 measured · Source: the US BTS Jun · 1,066 · 1,066 recorded · 1,058 measured · Source: the US BTS Jul · 1,182 · 1,182 recorded · 1,156 measured · Source: the US BTS Aug · 541 · 541 recorded · 541 measured · Source: the US BTS Sep · 458 · 458 recorded · 458 measured · Source: the US BTS Oct · 743 · 743 recorded · 739 measured · Source: the US BTS Nov · 700 · 700 recorded · 698 measured · Source: the US BTS Dec · 693 · 693 recorded · 688 measured · Source: the US BTS

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View the figures
Month of yearOn-time departuresAverage departure delayWith departure timeRecorded flights
Jan82.6%8.2 min547561
Feb82.6%15.5 min522548
Mar81.5%7.9 min724727
Apr82.9%8.1 min732735
May81.3%7.9 min957963
Jun72.0%16.7 min1,0581,066
Jul68.2%27.1 min1,1561,182
Aug77.5%13.2 min541541
Sep76.4%16.0 min458458
Oct80.1%11.4 min739743
Nov86.5%4.4 min698700
Dec79.2%10.5 min688693

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 77.6% 6,918
  • Delayed >15 min 21.3% 1,902
  • Cancelled 1.1% 97
  • 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

35
35 of 35
Flight numbersBy direction DeparturesOn time
DL384 BOS → SEA 658 87.9%
DL459 SEA → BOS 658 91.7%
AS306 SEA → BOS 655 80.9%
DL473 SEA → BOS 655 82.4%
DL324 BOS → SEA 654 75.7%
AS459 BOS → SEA 638 87.7%
AS460 SEA → BOS 617 72.6%
AS537 BOS → SEA 406 84.4%
AS536 SEA → BOS 401 79.7%
DL332 BOS → SEA 388 85.5%
DL474 SEA → BOS 374 70.2%
B66397 BOS → SEA 258 88.3%
B66398 SEA → BOS 258 48.2%
AS364 BOS → SEA 238 84.3%
B66497 BOS → SEA 185 83.5%
B66498 SEA → BOS 185 72.2%
B66197 BOS → SEA 147 49.3%
B66198 SEA → BOS 147 47.9%
AS819 BOS → SEA 136 60.5%
AS818 SEA → BOS 135 56.7%
AS304 BOS → SEA 121 66.9%
AS306 BOS → SEA 116 78.1%
AS215 BOS → SEA 85 84.7%
AS424 SEA → BOS 76 81.6%
DL2889 BOS → SEA 67 67.2%
AS214 SEA → BOS 54 70.4%
AS219 SEA → BOS 52 63.5%
AS338 BOS → SEA 52 84.3%
DL438 SEA → BOS 49 63.3%
AS393 BOS → SEA 45 86.7%
AS1337 BOS → SEA 44 48.8%
AS307 BOS → SEA 42 58.5%
AS309 BOS → SEA 36 82.4%
AS299 BOS → SEA 34 78.8%
DL412 SEA → BOS 31 90.3%

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 618 +14.9% 16 68.1%
June 2026 551 +8.7% 5 72.2%
May 2026 506 +12.2% 2 83.8%
April 2026 342 −12.3% 2 79.5%
March 2026 343 −10.0% 1 78.7%
February 2026 242 −13.6% 15 85.5%
January 2026 247 −17.7% 13 79.4%
December 2025 317 −14.6% 5 80.4%
November 2025 325 −12.9% 2 85.2%
October 2025 451 +56.6% 4 76.1%
September 2025 458 0 76.4%
August 2025 541 0 77.4%
July 2025 538 10 68.2%
June 2025 507 3 71.8%
May 2025 451 4 78.5%
April 2025 390 1 85.9%
March 2025 381 2 84.0%
February 2025 280 11 80.0%
January 2025 300 1 85.3%
December 2024 371 0 78.2%
November 2024 373 0 87.7%
October 2024 288 0 86.5%

How to read this chart

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