SEA → STLSeattle to St Louis

live

Direct flights from Seattle (SEA) to St Louis (STL): 7 nonstop departures observed each week across 1 airline. The median arrival is 21 minutes early. No cancellations were recorded across the 4 tracked flights. The nonstop covers 2,744 km, an estimated 4 hours 1 minutes in the air. Measured by Pro Flight Search from live flight boards at Seattle and St Louis. Updated 18 October 2026 at 11:22 UTC.

Today, SEA → STL

Sun 18 Oct · local times
  1. 09:40 AS647Alaska On scheduleGate N20 ·
  2. 18:03 AS618Alaska Sched 18:03Departure not confirmed by the board ·

Checked SEA board 04:22 · STL board 06:18

SEA Seattle heavy · +30
STL St Louis smooth · +14
2,744 km · ~4h 01m est.
dep bank 09:40–18:037x weekly
Running clean · 1 airline · 7x weekly · nonstop
71 / 100

route health from live SEA and STL delay boards

Median arrival delay is −21 min. 0 of 4 tracked legs cancelled in the sample. Will a delayed flight be cancelled? →

Median arrival−21 minacross the last 4 operated legs
Flight time~4h 01mestimated from route distance
Weekly departures7x1 direct airline on the leg

The week

scheduled departures · origin local time
06121824
Mon
Tue
Wed
Thu
Fri
Sat
Sun
Alaska Airlines

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 AirlinesAS

Flights AS647 09:40 daily · AS618 18:03 daily

History

operated legs · board outcomes
10-17AS618arrived−33
10-17AS647arrived−25
10-16AS618arrived−19
10-16AS647arrived−21

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 +30 min heavy 🌤 clear · ENE 6 kt Full SEA delay board →
STLSt Louis +14 min smooth 🌤 clear · N 0 kt Full STL delay board →

Weather lens

Current conditions put the pressure at STL: 40% odds of a 15+ minute delay and around +9 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 St Louis route actually runs

Pro Flight Search records official board updates for nonstop SEA to STL flights through the day: 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.

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 St Louis (STL) route reliability, measured from operated flights on official airport boards.

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

SEA to STL questions

Is SEA–STL running on time right now?

Mostly on schedule. The departure side at SEA is the weaker end, route health score 71/100. The airports section above carries the live status and delay window at both ends.

Morning or evening flight on SEA–STL?

Operators schedule morning departures around 09:40 and evening departures around 18:03 from SEA. Earlier flights typically land before destination-airport delays accumulate later in the day; check the STL delay card to confirm conditions when you'd arrive.

How long is the flight from SEA to STL?

Great-circle distance is 2,744 km. With typical jet cruise speed plus taxi, climb and descent, expect roughly 224–265 min gate-to-gate on this route.

How often does SEA–STL fly?

Alaska Airlines runs the route with about 14 flights a week (daily). Since one carrier owns the route, a single disruption tends to ripple through the day.