St Louis to Seattle (STL–SEA) — Airlines, Schedules & Connections

STL Airport Page →
1,705 mi airlines 21/wk
On-time Some delays Frequent delays
Flight Schedule 6 flights Verified 36m ago
Nonstop 1-Stop 2-Stop Hide separate tickets Hide overnight
  Flight Airline AC Dep Arr Dur OTP Sched  
AS473
AS Alaska
739
7:00 AM
EDT T1
9:42 AM
MDT
4h 42m
M T W T F S S
Prices
AS314
AS Alaska
7M9
2:44 PM
EDT T1
5:17 PM
MDT
4h 33m
M T W T F S S
Prices
AS388
AS Alaska
73J
3:50 PM
EDT T1
6:23 PM
MDT
4h 33m
M T W T F S S
Prices
AS618
AS Alaska
7M9
7:55 AM
MDT
1:51 PM
EDT
3h 56m
M T W T F S S
Prices
AS388
AS Alaska
73J
8:55 AM
MDT
2:51 PM
EDT
3h 56m
M T W T F S S
Prices
AS615
AS Alaska
739
6:07 PM
MDT
11:59 PM
EDT
3h 52m
M T W T F S S
Prices

No flights match your filters.

No nonstop flights on this route. connecting options below.

1-STOP
2-STOP Loading...
St Louis to Seattle
1 carrier, 21 flights/week nonstop.
1 Airlines 21 Flights/wk 1,705 mi 4h 33m nonstop -2h behind 63 1-stop hubs

STL–SEA is served by 1 airline with nonstop service. Alaska Airlines leads the route. The flight covers 1,705 miles in approximately 4h 33m. Beyond nonstop, 63 hubs offer 1-stop connections.

Airline Landscape

All carriers operating nonstop STL–SEA service, compared side by side.
Airline Freq/wk Aircraft Duration Dep OTP Alliance Codeshares
AS Alaska Airlines 21 739, 73J, 7M9 4h33-4h42 73% Oneworld
Aircraft on this route
739 Boeing 737-900 – AS
73J Boeing 737-900ER – AS
7M9 Boeing 737 MAX 9 – AS
Alliance coverage
Oneworld: AS (21 flights/wk, 100%)
OTP based on airport-level delay snapshots. Duration ranges reflect seasonal/directional variation.

Weekly Schedule Pattern

Nonstop flight frequency by day of week, STL to SEA direction.
Mon
3
flights
Tue
3
flights
Wed
3
flights
Thu
3
flights
Fri
3
flights
Sat
3
flights
Sun
3
flights
Departure time distribution
12 AM6 AM12 PM6 PM12 AM
Morning departures
Afternoon/evening departures
3
Nonstop flights
21
Outbound / wk
21
Return / wk

Connection Landscape

Beyond nonstop. 1-stop and 2-stop options for STL to SEA.
1-STOP
One-Stop Connections
63
Hubs
~6h
Fastest
~28h
Longest
Verified with published schedule alignment and minimum connection time.
2-STOP
Two-Stop Connections
3,011
Candidates
Two-stop connections loaded in the connections tab above.
Connections computed from published schedules with minimum connection time verification. Use the interactive explorer above the fold to filter by airline, tier, and layover time.

On-Time Performance

What to expect at each end of your journey.
Outbound
STL → SEA
73%
Moderate delays possible. Allow buffer time.
Departing
73%
Arriving
100%
Return
SEA → STL
94%
Generally reliable. Most flights run on time.
Departing
94%
Arriving
87%
OTP = percentage of flights arriving within 15 min of schedule. Based on airport-level delay snapshots. STL delays → SEA delays →

Travel Essentials

Practical planning for this route.
Time Difference
-2h
Seattle is 2 hours behind St Louis.
STL: EDT · SEA: MDT

When it's 6:00 PM in St Louis, it's 4:00 PM in Seattle.
Distance & Flight Time
1,705 mi / 2,744 km
Nonstop flight time is approximately 4h 33m to 4h 42m.
Getting from SEA

Link Light Rail from the airport station (inside the terminal) to downtown Seattle takes 38 minutes ($3.50). No transfers needed; trains run 5am to 1am daily.Taxis and ride-shares to downtown cost $35–55. For Bellevue and Eastside destinations (across Lake Washington), ride-share is faster than Link. Car rentals are in the consolidated rental facility; take the free shuttle from baggage claim. Sound Transit buses serve Tacoma, Renton, and Federal Way.

Seattle Climate

Marine west coast climate. Winters are mild but persistently grey and rainy (3–9°C). Snow is rare at sea level but can occur December through February, causing significant disruptions when it does. The airport sits between Seattle and Tacoma in an area that receives more fog and low cloud than downtown Seattle.

Summers are famously pleasant (18–25°C) with low humidity and mostly clear skies, one of the best flying climates in the US from June through September. The wettest months are November through January.

STL–SEA Quick Facts

Key statistics for the St Louis to Seattle route.
Route details
Distance1,705 mi / 2,744 km
Flight time4h 33m to 4h 42m
Time difference-2 hours
Airlines (nonstop)1
Weekly flights21 out / 21 return
1-stop connections63 hubs
Origin: STL
IATA / ICAOSTL / KSTL
TimezoneAmerica/Indiana/Vincennes
Passengers/yr15.6M
Elevation618 ft / 188 m
Destination: SEA
IATA / ICAOSEA / KSEA
TimezoneAmerica/Boise
Passengers/yr52.6M
Elevation433 ft / 132 m

Frequently Asked Questions

Common questions about STL to SEA flights.
Nonstop flights from St. Louis Lambert International Airport to Seattle–Tacoma International Airport take approximately 4h 33m to 4h 42m. The route covers 1,705 miles.
1 airline operates nonstop service: Alaska Airlines.
There are approximately 21 nonstop flights per week from STL to SEA. The return direction has about 21 weekly flights.
Yes, 1-stop connections are available through ASE, FAR, ICT, HOU, SBA, BFI, SBD, BZN, EGE, ELP, OKC, MRY, BUR, CVG, SJC, PSP, IND, SJD, SAT, CMH, ABQ, PVR, MIA, IAD, SFO, SMF, CUN, BWI, LAX, ATL, IAH, PHL, MSP, ORD, MDW, DFW, YYZ, DEN, CHS, CLE, SLC, MCO, LAS, AUS, MCI, MSY, RDU, PHX, SAN, OMA, DAL, TPA, FRA, DTW, BNA, DCA, FLL, MKE, BOS, CLT, EWR, RSW and PIT. These options provide additional schedule flexibility.
Seattle is 2 hours behind St Louis.
Yes, return flights from SEA to STL are available. Use the direction toggle at the top to view the return schedule.
Click the 'Search Flights' button to check availability and prices on Google Flights. You can also compare airlines and schedules on this page to find the best option.
See the On-Time Performance section for the latest delay data at both airports. This shows departure and arrival reliability to help you plan.
Route data is updated regularly from official airline schedules. On-time performance data comes from recent airport delay snapshots.

Flights from STL to SEA

St. Louis Lambert International Airport (STL) and Seattle–Tacoma International Airport (SEA) are connected by nonstop service from Alaska Airlines. With 21 weekly departures, this is a well served route.

STL to SEA Flight Duration and Schedule

Nonstop flight time from STL to SEA ranges from 4 hours 33 minutes to 4 hours 42 minutes. The route covers a distance of 1,705 miles (2,744 km). There are approximately 21 weekly flights outbound and 21 return, totaling 42 flights per week in both directions.

Connecting Options and Alternatives

63 one-stop connections are available, with the fastest taking approximately 6 hours via ASE. Two-stop connections are also available via intermediate hubs.