Seattle (SEA) to St Louis (STL)
Flight time
≈ 4h 13m
Bearing
99° E
Seattle (SEA) to St Louis (STL) is 1,705 miles (2,744 km) as the crow flies — the great-circle baseline most distance-based mileage programs credit.
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What actually flies SEA–STL
Filed traffic dataIn July 2026, Alaska Airlines operated the most departures, one of 3 carriers flying nonstop SEA–STL; the Boeing 737 MAX 9 was the most common aircraft at 39% of departures; flights ran 86% full.
Departures
247
July 2026
Seats
43,292
both directions
Passengers
37,312
both directions
Load factor
86.2%
RPM ÷ ASM
Who flies SEA–STL?
Alaska Airlines operated the most nonstop SEA–STL departures in July 2026 (185), one of 3 carriers on the route.
- AS
185 departures · 32,811 seats
Share of departures74.9%82.9%
Load
- WN
61 departures · 10,409 seats
Share of departures24.7%96.4%
Load
- DL
1 departures · 72 seats
Share of departures0.4%90.3%
Load
What plane flies SEA–STL?
In July 2026, the Boeing 737 MAX 9 flew 39% of SEA–STL departures — more than any other aircraft type.
- Boeing 737 MAX 9
97 departures · 82.8% load
39.3% - Boeing 737-900ER
81 departures · 82.6% load
32.8% - Boeing 737 MAX 8
41 departures · 95.3% load
16.6% - Boeing 737-800
20 departures · 95.4% load
8.1% - Boeing 737-700
7 departures · 99.1% load
2.8% - Boeing 757-200
1 departures · 90.3% load
0.4%
How has SEA–STL traffic changed?
Nonstop SEA–STL departures rose from 224 in August 2025 to 247 in July 2026.
Monthly nonstop SEA–STL traffic, trailing 12 months through July 2026. Bars scale to the busiest month; months with no filed service show as zero.
August 2025
224 departures · 34,636 passengers
89.8%
Load
September 2025
197 departures · 29,437 passengers
87.6%
Load
October 2025
121 departures · 18,523 passengers
86.4%
Load
November 2025
100 departures · 15,096 passengers
85.9%
Load
December 2025
108 departures · 16,005 passengers
84.7%
Load
January 2026
73 departures · 10,723 passengers
83.0%
Load
February 2026
75 departures · 10,879 passengers
82.2%
Load
March 2026
102 departures · 16,029 passengers
88.8%
Load
April 2026
118 departures · 17,412 passengers
83.8%
Load
May 2026
162 departures · 23,407 passengers
82.2%
Load
June 2026
236 departures · 35,680 passengers
86.7%
Load
July 2026
247 departures · 37,312 passengers
86.2%
Load
By direction
Each direction is filed separately — they rarely match.
SEA → STL
84.1% full
124 departures · 18,237 passengers
STL → SEA
88.3% full
123 departures · 19,075 passengers
Nonstop SEA–STL traffic has been filed since 2025.
Source: US DOT BTS Form 41 T-100 Segment (All Carriers). Data through July 2026; filings from 2025. Public domain (US Government work).
The airports
Frequently asked
How far is Seattle (SEA) from St Louis (STL)?
SEA to STL is 1,705 miles (2,744 km / 1,482 nautical miles) measured great-circle — the shortest path over the surface of the Earth.
How long is the flight from SEA to STL?
A nonstop covers the 1,705-mile great-circle distance in roughly 4h 13m of block time, before winds. Actual schedules vary a few percent by direction and aircraft.
What plane flies SEA–STL?
In July 2026, the Boeing 737 MAX 9 flew the largest share of departures (39.3%), followed by the Boeing 737-900ER (32.8%).
What mileage do I earn flying SEA–STL?
Distance-based programs credit off the 1,705-mile great-circle figure, then apply your fare-class earning rate. Revenue-based programs credit off the fare instead.
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