St. Louis Lambert International ⇄ Seattle-Tacoma International STL–SEA
Airlines flew 1,763 flights between St. Louis Lambert International STL in St Louis, MO and Seattle-Tacoma International SEA in Seattle, WA in the twelve months to July 2026, both directions together: 265,139 passengers in 308,013 seats, 86% of them filled, and 223,121 pounds of freight. 1,709 miles, about 235 minutes in the air, on 5 airlines: Alaska Airlines Inc. (1,553), Southwest Airlines Co. (206), United Air Lines Inc. (2), American Airlines Inc. (1) and 1 more. Planning to fly it yourself? The weather and winds along this route right now.
Flights by month both directions
By month, as a table
| flights | |
|---|---|
| 1/25 | 66 |
| 2/25 | 76 |
| 3/25 | 104 |
| 4/25 | 118 |
| 5/25 | 160 |
| 6/25 | 231 |
| 7/25 | 244 |
| 8/25 | 224 |
| 9/25 | 197 |
| 10/25 | 121 |
| 11/25 | 100 |
| 12/25 | 108 |
| 1/26 | 73 |
| 2/26 | 75 |
| 3/26 | 102 |
| 4/26 | 118 |
| 5/26 | 162 |
| 6/26 | 236 |
| 7/26 | 247 |
Passengers by month
By month, as a table
| passengers | |
|---|---|
| 1/25 | 9,891 |
| 2/25 | 9,881 |
| 3/25 | 15,133 |
| 4/25 | 16,423 |
| 5/25 | 23,247 |
| 6/25 | 34,765 |
| 7/25 | 37,550 |
| 8/25 | 34,636 |
| 9/25 | 29,437 |
| 10/25 | 18,523 |
| 11/25 | 15,096 |
| 12/25 | 16,005 |
| 1/26 | 10,723 |
| 2/26 | 10,879 |
| 3/26 | 16,029 |
| 4/26 | 17,412 |
| 5/26 | 23,407 |
| 6/26 | 35,680 |
| 7/26 | 37,312 |
The airlines twelve months, both directions
| Airline | Flights | Passengers | Seats filled | Service |
|---|---|---|---|---|
| Alaska Airlines Inc. AS | 1,553 | 232,122 | 85% | scheduled passenger service |
| Southwest Airlines Co. WN | 206 | 32,500 | 96% | scheduled passenger service |
| United Air Lines Inc. UA | 2 | 280 | 81% | scheduled passenger service |
| American Airlines Inc. AA | 1 | 172 | 100% | scheduled passenger service |
| Delta Air Lines Inc. DL | 1 | 65 | 90% | charter passenger service |
The aircraft as the airlines report their types
| Aircraft | Flights | Seats a flight | Passengers |
|---|---|---|---|
| Boeing 737-900ER | 715 | 178 | 107,482 |
| Boeing B737 Max 900 | 673 | 178 | 101,035 |
| Boeing 737-800 | 202 | 165 | 30,477 |
| Boeing B737 Max 800 | 111 | 171 | 17,677 |
| Boeing 737-700/700LR/Max 7 | 61 | 142 | 8,403 |
| Boeing 757-200 | 1 | 72 | 65 |
STL → SEA this direction alone · flown January 2025 to July 2026
879 flights of 891 scheduled, 133,144 passengers in 154,241 seats, 122,805 pounds of freight. Alaska Airlines Inc. 775; Southwest Airlines Co. 104.
SEA → STL this direction alone · flown January 2025 to July 2026
884 flights of 894 scheduled, 131,995 passengers in 153,772 seats, 100,316 pounds of freight, 4,277 pounds of mail. Alaska Airlines Inc. 778; Southwest Airlines Co. 102; United Air Lines Inc. 2; American Airlines Inc. 1; Delta Air Lines Inc. 1.
Source: the Bureau of Transportation Statistics' T-100 Segment table (all carriers). A flight is one departure performed on this segment; seats and passengers are the airlines' own monthly reports; "seats filled" is passengers divided by seats. The miles are the DOT's great-circle distance. Both ends: St. Louis Lambert International STL and Seattle-Tacoma International SEA; all routes.