Seattle to Denver (SEA–DEN) — Airlines, Schedules & Connections
No flights match your filters.
No scheduled airline flights on this route — it's flown by charter / private operators (). No nonstop flights on this route. connecting options below.
Most recently operated nonstop flights — the month shown is when each was last scheduled. Most destinations remain reachable with a connection.
No discontinued nonstop flights on record for this route.
SEA–DEN is served by 6 airlines with nonstop service. United Airlines, Southwest Airlines and Alaska Airlines lead the route. The flight covers 1,022 miles in approximately 2h 48m. Beyond nonstop, 1-stop connecting options are also available.
Airline Landscape
| Airline | Freq/wk | Aircraft | Duration | Dep OTP | Alliance | Codeshares |
|---|---|---|---|---|---|---|
| UA United Airlines Also: CM, LX | 64 | 320, 32Q, 738, 7M8, A21N | 2h41-2h57 | Star Alliance | CM, LX | |
| WN Southwest Airlines | 64 | 738, 73H, 7M8, 7S7 | 2h29-2h50 | – | – | |
| AS Alaska Airlines Also: AY, DE, FI, HA, JX, KE, QR | 54 | 738, 739, 73H, 73J, 7M9, B39M | 2h44-2h54 | Oneworld | AY, DE, FI, HA, JX, KE, QR | |
| DL Delta Air Lines Also: AF, KE, SK, VS, WS | 21 | 223, BCS3 | 2h30-2h53 | SkyTeam | AF, KE, SK, VS, WS | |
| F9 Frontier Also: Y4 | 14 | 321, 32Q | 2h52-3h05 | – | Y4 | |
| SY Sun Country Airlines | 0 | – | – | – | – |
Weekly Schedule Pattern
Connection Landscape
On-Time Performance
Other ways to reach Denver from Seattle
| Metric | SEA→DEN | BFI→DEN | PAE→DEN |
|---|---|---|---|
| Distance from SEA | – | 5 mi | 32 mi |
| Nonstop airlines | 6 | 6 | 1 |
| Weekly flights | 345 | 1 | 1 |
| Flight time | 2h 48m | 2h 5m | 2h 45m |
| Departure OTP | 100% | – | – |
Travel Essentials
SEA: PDT · DEN: MDT
When it's 6:00 PM in Seattle, it's 7:00 PM in Denver.
Link Light Rail runs from downtown Seattle (Westlake station) to the airport in 38 minutes ($3.50 peak). Trains run every 6–12 minutes during peak hours from 5am to 1am. Ride-shares run $30–50 from downtown; SR-99 and I-5 can be heavily congested southbound during afternoon rush (3–7pm).
Sound Transit 574 express bus serves Tacoma ($2.50–4). Sounder commuter rail connects Tacoma to the airport area via a shuttle.
RTD A Line runs to Denver Union Station (37 min, $10.50) with connections to light rail and bus routes. Taxis have meters; expect $55–65 to downtown.DEN's tent-roof Jeppesen Terminal is a single building; all three concourses connect via the underground automated train. Rental cars are on level 5. For ski resorts, shuttle services depart from Ground Transportation.
Semi-arid with 300+ days of sunshine. Summers are dry and warm (27–34°C) with afternoon thunderstorms that produce dramatic but brief delays. Winters bring cold temperatures (−8 to 5°C) and heavy blizzards that can shut down ground operations.
Spring snowstorms can be heavier than midwinter ones. Altitude (5,430 ft) means low humidity year-round; stay hydrated.
SEA–DEN Quick Facts
Frequently Asked Questions
Seattle to Denver: Tech Corridor and Mountain Gateway
SEA-DEN connects the Pacific Northwest's largest metro to the central Rocky Mountain hub. Alaska, United, Delta, Southwest, and Frontier combine for 12 to 17 daily nonstops. Block time is 2 hours 40 minutes eastbound and about 3 hours westbound. The route serves tech industry traffic between Seattle's Amazon, Microsoft, and Boeing campuses and Denver's growing tech sector. It also carries heavy ski season traffic from Seattle to Colorado resorts accessible through DEN. Alaska and United hold the largest shares, reflecting their respective hub positions at SEA and DEN.
Hub Dynamics at Both Ends
Both airports function as major connecting hubs. Seattle is Alaska Airlines' primary hub, offering onward connections across the Pacific Northwest and to Asia. Denver is United's second-largest hub behind Houston, with connections to the Mountain West, Great Plains, and seasonal international routes. A direct SEA-DEN ticket also opens connecting possibilities on both ends: through SEA to Portland, Boise, or Alaska, and through DEN to Aspen, Jackson Hole, or Kansas City. Denver's A Line rail makes the airport-to-downtown connection straightforward at $10.50 and 37 minutes. Seattle's Link Light Rail reaches SEA-TAC from downtown in about 40 minutes for $3.25.