Denver to Seattle (DEN–SEA) — Airlines, Schedules & Connections
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No nonstop flights on this route. connecting options below.
DEN–SEA is served by 5 airlines with nonstop service. United Airlines, Alaska Airlines and Delta Air Lines lead the route. The flight covers 1,022 miles in approximately 2h 36m. Beyond nonstop, 129 hubs offer 1-stop connections.
Airline Landscape
| Airline | Freq/wk | Aircraft | Duration | Dep OTP | Alliance | Codeshares |
|---|---|---|---|---|---|---|
| UA United Airlines Also: CM | 46 | 319, 320, 32Q, 738, 739, B39M | 2h59-3h01 | Star Alliance | CM | |
| AS Alaska Airlines Also: DE, FI, HA, JL, JX, KE, QR | 43 | 739, 73H, 73J, 7M8 | 3h02-3h07 | Oneworld | DE, FI, HA, JL, JX, KE, QR | |
| DL Delta Air Lines Also: AF, KE, VS, WS | 28 | 223, E7W | 2h54-3h06 | SkyTeam | AF, KE, VS, WS | |
| WN Southwest Airlines | 22 | 737, 738, 7M8, B38M | 2h37-3h | – | – | |
| F9 Frontier Also: Y4 | 14 | 321 | 2h36-3h12 | – | Y4 |
Weekly Schedule Pattern
Connection Landscape
Other ways to reach Seattle from Denver
| Metric | DEN→SEA | COS→SEA | EGE→SEA |
|---|---|---|---|
| Distance from DEN | – | 73 mi | 120 mi |
| Nonstop airlines | 5 | 1 | 1 |
| Weekly flights | 302 | – | – |
| Flight time | 2h 36m | 1h 52m | 3h 7m |
| Departure OTP | 96% | – | – |
Travel Essentials
DEN: MDT · SEA: PDT
When it's 6:00 PM in Denver, it's 5:00 PM in Seattle.
RTD A Line commuter rail runs from Denver Union Station to the airport (37 min, $10.50). Trains depart every 15 minutes during peak hours. The airport is 25 miles northeast of downtown; ride-shares cost $35–55 and take 30–45 minutes depending on I-70 traffic.Economy parking in lots 4–6 connects via free shuttle. Mountain shuttle services depart from Jeppesen Terminal's Ground Transportation level.
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.
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.
DEN–SEA Quick Facts
Frequently Asked Questions
Denver to Seattle: A High-Frequency Western Hub Corridor
DEN–SEA links two of the West's fastest-growing major airports. Denver International serves United's western hub, and Seattle-Tacoma is Alaska Airlines' primary base. The route carries a dense schedule across five carriers, with combined daily frequencies exceeding most domestic routes of comparable distance. Block time is 2 hours 20 minutes westbound and 2 hours 50 minutes eastbound. The corridor carries tech workers commuting between Denver's growing tech sector and Seattle's established base at Amazon, Microsoft, and Boeing, alongside ski-season leisure traffic and Pacific Northwest outdoor travelers heading east.
Carrier Competition and Connecting Traffic
Alaska and United dominate frequency on this corridor. Frontier and Southwest provide lower-cost alternatives with less schedule depth. Delta adds service connecting through its Seattle hub to its broader network. Passengers connecting through Denver reach DFW, ORD, EWR, and transatlantic routes. Those connecting through Seattle access Alaska's Pacific and transcontinental network. The route is one of the few domestic corridors where two full-service hubs sit at opposite ends with competing hub-to-hub frequencies.