SEA → BOSSeattle to Boston

live

Direct flights from Seattle (SEA) to Boston (BOS): 21 nonstop departures observed each week across 3 airlines. 75% of the last 55 operated flights arrived within 15 minutes of schedule. The median arrival is 21 minutes early. 1 of the 55 tracked flights was cancelled. The nonstop covers 4,006 km, an estimated 5 hours 38 minutes in the air. Measured by Pro Flight Search from live flight boards at Seattle and Boston. Updated 17 August 2026 at 16:26 UTC.

SEA Seattle smooth · +10
BOS Boston smooth · +0
4,006 km · ~5h 38m est.
dep bank 06:03–23:4521x weekly
Runs mixed · 3 airlines · 21x weekly · nonstop
75% on time

of the last 55 operated SEA → BOS flights arrived within 15 minutes

Median arrival delay is −21 min. 1 of 55 tracked legs cancelled in the sample. Will a delayed flight be cancelled? →

Search live fares for this route →
Median arrival−21 minacross the last 55 operated legs
Flight time~5h 38mestimated from route distance
Weekly departures21x3 direct airlines on the leg
Cancelled1.8%recent route rate · 1 of 55

Current nonstop fares

SEA → BOS · one way · economy · 1 adult

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TodayChecking…Direct airline fares
TomorrowChecking…Direct airline fares
In one weekChecking…Direct airline fares

The week

scheduled departures · origin local time
06121824
Mon
Tue
Wed
Thu
Fri
Sat
Sun
Alaska AirlinesDelta Air LinesJetBlue Airways

Each mark is a scheduled departure at its origin-local time, observed operating in the last 7 days. Today is highlighted.

Who flies it

observed on the boards · 7 days
Alaska AirlinesAS88% on time

Flights AS1505 06:03 Mo Th Fr Sa Su · AS306 08:23 daily · AS219 10:13 daily · AS460 15:36 daily

Delta Air LinesDL85% on time

Flights DL459 07:38 daily · DL438 11:15 daily · DL474 15:59 Mo Tu We Th Fr Su · DL473 23:13 daily

JetBlue AirwaysB620% on time

Flights B6398 11:40 daily · B6198 23:45 daily

History

operated legs · board outcomes
08-17AS1505arrived−47
08-17AS306departed+12
08-16AS1505dep +15 → arr−24
08-16AS219dep +33 → arr−6
08-16AS306dep +33 → arr−15
08-16AS460dep +9 → arr−27
08-16AS536dep +13 → arr−34
08-16B6198dep +44 → arr−5
08-16B6398dep +74 → arr+25
08-16DL438dep +14 → arr−34
08-16DL459dep +18 → arr−21
08-16DL473dep +20 → arr−30
08-16DL474dep +19 → arr−20
08-15AS1505dep +17 → arr−30
08-15AS219dep +10 → arr−35
08-15AS306dep +44 → arr−9
08-15AS460dep +61 → arr+16
08-15B6198dep +135 → arr+84
08-15B6398dep +165 → arr+111
08-15DL438dep +60 → arr+40
08-15DL459dep +34 → arr−18
08-15DL473dep +25 → arr−21
08-14AS1505dep +12 → arr−40
08-14AS219dep +32 → arr−24
08-14AS306dep +44 → arr+141
08-14AS460dep +9 → arr−46
08-14AS536dep +71 → arr+21
08-14B6198cancelledCNX
08-14B6398dep +210 → arr+161
08-14DL438dep +76 → arr+27
08-14DL459dep +40 → arr−22
08-14DL473dep +38 → arr−14
08-14DL474dep +258 → arr+207
08-13AS1505dep +9 → arr−45
08-13AS219dep +36 → arr−6
08-13AS306dep +25 → arr−23
08-13AS460dep +31 → arr−22
08-13AS536dep +31 → arr−20
08-13B6198dep +61 → arr+10
08-13B6398dep +157 → arr+92

Actual board outcomes rather than schedules, paired departure and arrival per flight and day.

Full board history, day by day →

Airports right now

live boards
SEASeattle +10 min smooth 🌤 mostly cloudy · SSE 3 kt Full SEA delay board →
BOSBoston +0 min smooth ⛅ overcast · S 10 kt Full BOS delay board →

Weather lens

Current conditions put the pressure at BOS: 50% odds of a 15+ minute delay and around +26 min expected when it bites, measured from this route's own weather-matched delay history. See live delays → · Weather risk by airport →

How the Seattle to Boston route actually runs

Pro Flight Search tracks every published board update for nonstop SEA to BOS flights: schedules, estimates, gate pushes and actual departures. The verdict above comes from operated flights, so it reflects what this route does rather than what the timetable promises. Fares link straight to the operating airline with no markups.

Planning around a delay? Live airport delays · Weather delay risk map · Will a delayed flight be cancelled? · Do planes make up time in the air? · How we measure

Cite this data

Journalists, bloggers, and researchers may cite this page with attribution and a link to Pro Flight Search.

Suggested citation

Pro Flight Search — Seattle (SEA) to Boston (BOS) route reliability, measured from operated flights on official airport boards.

Canonical URL
https://proflightsearch.com/search-flights/SEA-BOS
How we measure this →

SEA to BOS questions

Is SEA–BOS running on time right now?

Some delays possible. The departure side at SEA is the weaker end, route health score 63/100. The airports section above carries the live status and delay window at both ends.

Morning or evening flight on SEA–BOS?

Operators schedule morning departures around 06:03 and evening departures around 23:13 from SEA. Earlier flights typically land before destination-airport delays accumulate later in the day; check the BOS delay card to confirm conditions when you'd arrive.

How long is the flight from SEA to BOS?

Great-circle distance is 4,006 km. With typical jet cruise speed plus taxi, climb and descent, expect roughly 313–373 min gate-to-gate on this route.

How often does SEA–BOS fly?

3 carriers operate this route, around 73 flights a week between them. Compare carrier days and times in the airline list above.