Denver International ⇄ Seattle-Tacoma International DEN–SEA
Airlines flew 13,321 flights between Denver International DEN in Denver, CO and Seattle-Tacoma International SEA in Seattle, WA in the twelve months to July 2026, both directions together: 1,819,887 passengers in 2,092,561 seats, 87% of them filled, and 62,586,510 pounds of freight. 1,024 miles, about 147 minutes in the air, on 12 airlines: United Air Lines Inc. (3,793), Alaska Airlines Inc. (3,088), Southwest Airlines Co. (2,667), Delta Air Lines Inc. (1,725) and 8 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 | 953 |
| 2/25 | 873 |
| 3/25 | 1,006 |
| 4/25 | 1,025 |
| 5/25 | 1,182 |
| 6/25 | 1,331 |
| 7/25 | 1,372 |
| 8/25 | 1,339 |
| 9/25 | 1,209 |
| 10/25 | 1,166 |
| 11/25 | 969 |
| 12/25 | 988 |
| 1/26 | 923 |
| 2/26 | 864 |
| 3/26 | 953 |
| 4/26 | 1,029 |
| 5/26 | 1,153 |
| 6/26 | 1,316 |
| 7/26 | 1,412 |
Passengers by month
By month, as a table
| passengers | |
|---|---|
| 1/25 | 112,127 |
| 2/25 | 106,477 |
| 3/25 | 127,255 |
| 4/25 | 133,689 |
| 5/25 | 165,479 |
| 6/25 | 186,304 |
| 7/25 | 204,979 |
| 8/25 | 202,035 |
| 9/25 | 171,901 |
| 10/25 | 159,436 |
| 11/25 | 125,010 |
| 12/25 | 131,752 |
| 1/26 | 112,844 |
| 2/26 | 106,434 |
| 3/26 | 123,455 |
| 4/26 | 130,644 |
| 5/26 | 158,982 |
| 6/26 | 190,193 |
| 7/26 | 207,201 |
The airlines twelve months, both directions
| Airline | Flights | Passengers | Seats filled | Service |
|---|---|---|---|---|
| United Air Lines Inc. UA | 3,793 | 569,113 | 88% | charter cargo service, charter passenger service, scheduled passenger service |
| Alaska Airlines Inc. AS | 3,088 | 476,858 | 88% | scheduled passenger service |
| Southwest Airlines Co. WN | 2,667 | 406,557 | 90% | scheduled passenger service |
| Delta Air Lines Inc. DL | 1,725 | 175,358 | 77% | charter passenger service, scheduled passenger service |
| Frontier Airlines Inc. F9 | 851 | 162,051 | 86% | scheduled passenger service |
| Air Transport International 8C | 745 | 0 | charter cargo service | |
| SkyWest Airlines Inc. OO | 443 | 29,378 | 88% | scheduled passenger service |
| Sun Country Airlines d/b/a MN Airlines SY | 4 | 203 | 27% | charter passenger service |
| American Airlines Inc. AA | 2 | 319 | 88% | scheduled passenger service |
| ABX Air Inc ABX | 1 | 0 | scheduled cargo service | |
| Horizon Air QX | 1 | 50 | 66% | scheduled passenger service |
| Atlas Air Inc. 5Y | 1 | 0 | 0% | charter passenger service |
The aircraft as the airlines report their types
| Aircraft | Flights | Seats a flight | Passengers |
|---|---|---|---|
| Boeing 737-800 | 2,483 | 167 | 357,438 |
| Boeing 737-900ER | 2,220 | 178 | 348,562 |
| Boeing B737 Max 800 | 1,885 | 173 | 288,367 |
| Boeing B737 Max 900 | 1,697 | 178 | 264,276 |
| Airbus Industrie A321-200n | 952 | 216 | 178,719 |
| A220-300 BD-500-1A11 | 902 | 130 | 92,999 |
| Boeing 767-300/300ER | 746 | 0 | 0 |
| Airbus Industrie A320-100/200 | 540 | 151 | 71,646 |
| Embraer ERJ-175 | 444 | 76 | 29,428 |
| A200-100 BD-500-1A10 | 443 | 109 | 39,838 |
| Boeing 737-700/700LR/Max 7 | 395 | 140 | 50,523 |
| Airbus Industrie A320-200n | 236 | 186 | 39,629 |
| Airbus Industrie A321Neoxlr | 189 | 229 | 37,161 |
| Airbus Industrie A319 | 178 | 126 | 19,880 |
| Boeing 757-200 | 4 | 102 | 365 |
| Boeing 737-900 | 3 | 178 | 527 |
| Boeing 757-300 | 2 | 234 | 287 |
| B787-900 Dreamliner | 1 | 257 | 242 |
| Boeing 747-400 | 1 | 189 | 0 |
DEN → SEA this direction alone · flown January 2025 to July 2026
6,677 flights of 6,325 scheduled, 912,808 passengers in 1,047,131 seats, 34,229,299 pounds of freight, 268,694 pounds of mail. United Air Lines Inc. 1,902; Alaska Airlines Inc. 1,547; Southwest Airlines Co. 1,337; Delta Air Lines Inc. 864; Frontier Airlines Inc. 425; Air Transport International 374; SkyWest Airlines Inc. 222; Sun Country Airlines d/b/a MN Airlines 3; American Airlines Inc. 1; ABX Air Inc 1; Horizon Air 1.
SEA → DEN this direction alone · flown January 2025 to July 2026
6,644 flights of 6,334 scheduled, 907,079 passengers in 1,045,430 seats, 28,357,211 pounds of freight, 374,315 pounds of mail. United Air Lines Inc. 1,891; Alaska Airlines Inc. 1,541; Southwest Airlines Co. 1,330; Delta Air Lines Inc. 861; Frontier Airlines Inc. 426; Air Transport International 371; SkyWest Airlines Inc. 221; Atlas Air Inc. 1; American Airlines Inc. 1; Sun Country Airlines d/b/a MN Airlines 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: Denver International DEN and Seattle-Tacoma International SEA; all routes.