Submit feedbackSubmit feedbackDecember departures from Seattle (All Airports) (SEAA) to Denver (All Airports) (DENA) see a mix of business and holiday leisure travelers. Expect higher search volume and fares around mid-December and the week surrounding Christmas; book 3–8 weeks ahead for best prices. Direct flights are plentiful on Alaska Airlines, United, Delta, and Southwest; consider early-morning departures for fewer delays. If you’re accessing SEA from nearby cities like Tacoma, Bellevue, Everett, Portland or even Vancouver BC, allow extra ground transit time for holiday traffic and winter conditions. CTA: Compare prices now and set a price alert for cheap flights from Seattle (All Airports) (SEAA) to Denver (All Airports) (DENA) this December.
A nonstop flight from Seattle (All Airports) (SEAA) to Denver (All Airports) (DENA) typically takes about 2 hours 45 minutes to 3 hours under normal conditions. December weather and air traffic can add small delays, so allow an extra 30–60 minutes buffer when planning connections or ground transport in Denver.
December fares vary widely: expect $120–$350 round-trip for economy on major carriers when booked 3–8 weeks out; holiday peak (mid-December and the week of Christmas) often pushes fares to $350–$600. Book early, monitor price alerts, and consider mid-week departures (Tuesday/Wednesday) to find the best cheap flights.
Seattle (All Airports) (SEAA) includes Seattle–Tacoma International (SEA) and regional access from King County areas like Bellevue, Everett, and Tacoma. In December allow extra time for light rail, shuttles, or ride-share pickups due to holiday traffic and potential winter weather; plan 60–90 minutes to clear ground transport during busy morning/evening windows.
Nonstop flights generally have higher reliability for a short route like Seattle to Denver because you avoid the additional risk of missed connections. However, December winter storms can impact any flight; when reliability is crucial, choose a direct flight, earlier departure times, and book with carriers known for robust winter operations.
Denver in December is cold with frequent snow—pack insulated layers, a warm coat, waterproof shoes, and sun protection for high-altitude sun. Keep a travel umbrella and slip-resistant footwear accessible for airport connections, and ensure carry-on liquids comply with TSA rules to speed security.
For domestic flights during December holiday travel, arrive at least 90 to 120 minutes before scheduled departure to allow for crowding, TSA lines, and winter-related delays. If you need to check baggage or travel during peak holiday times, err on the side of 2 hours or more.
Arriving at Denver (All Airports) (DENA) in December places you at the doorstep of world-class ski areas and urban destinations such as Boulder, Aurora, Colorado Springs, Vail, and Aspen. The A Line rail to Union Station remains a cost-effective downtown option; shuttles and rental cars are common choices for mountain transfers. Expect winter road conditions—carry tire chains if renting a two-wheel-drive vehicle and confirm shuttle times around holiday dates. CTA: Book transfers early for December arrivals and compare shuttle vs. rental car options to get the best prices from Denver (All Airports) (DENA).
From Denver (All Airports) (DENA) the fastest options to Boulder are shuttle services, car rentals, or ride-shares, typically taking 30–45 minutes depending on traffic and weather. In December watch for snowy conditions and check Colorado Department of Transportation updates; pre-booking shuttle transfers or renting an AWD vehicle is recommended for mountain travel.
Winter storms in Colorado can cause flight delays or cancellations, particularly during heavy snowfall or high winds. While Denver (All Airports) (DENA) operates with strong de-icing and runway snow-removal capabilities, travelers should expect occasional disruptions and monitor airline alerts; plan extra connection time if you have onward travel.
Arrival procedures at Denver (All Airports) (DENA) follow standard domestic protocols—claim checked baggage at the carousel and use ground transportation on level arrivals. December holiday crowds can increase baggage wait times and ground-transport queues, so expect longer waits for shuttles and rideshares; consider pre-booked transfers for convenience.
Seattle (All Airports) (SEAA) departures may be influenced by Pacific Northwest events such as holiday light displays, Seattle Christkindlmarkets, and seasonal concerts, increasing traveler volume in December. Denver (All Airports) (DENA) arrivals commonly spike for Denver Parade of Lights, Christkindl Market Denver, and the start of ski season in nearby resorts like Vail and Breckenridge—opening weekends draw many visitors. Plan flights around major event dates to avoid surges and secure early bookings. CTA: If you’re traveling for a specific December event, book flights and lodging early to lock in the best deals.
The best time to fly from Seattle (All Airports) (SEAA) to Denver (All Airports) (DENA) in December is mid-week (Tuesday–Thursday) and early morning departures, which typically offer lower fares and fewer weather-related knock-on delays. Avoid peak holiday dates (around December 21–26 and New Year’s Eve) when fares and crowds surge. If possible, book flights outside of the main holiday windows and aim for the first departures of the day to maximize on-time performance. CTA: Search flexible dates to find the best combination of price and timing for December travel.
For the relatively short Seattle (All Airports) (SEAA) to Denver (All Airports) (DENA) route, nonstop flights generally save time and reduce the chance of missed connections—particularly valuable during December winter weather. Connecting itineraries can be cheaper but introduce added risk and longer total travel time, with common hubs like Salt Lake City or Phoenix. If cost is the priority and you can tolerate longer travel times, consider a single-connection flight; for reliability and convenience during holiday travel, choose a nonstop. CTA: Compare nonstop and one-stop options to find the right balance for your December trip.
Alaska Airlines: frequent nonstops from SEA with strong West Coast coverage, competitive fares, and Mileage Plan benefits. United Airlines: reliable schedules with multiple daily options and strong loyalty perks for MileagePlus members; often competitive on connecting fares. Delta Air Lines: consistent service and SkyMiles benefits, with solid winter operations. Southwest Airlines: value-oriented fares with two free checked bags and flexible change policies—useful during December travel. When comparing airlines, factor in baggage fees, change policies (especially useful for holiday plans), and schedule frequency. CTA: Compare fares across these carriers for December and book the option that balances price, baggage needs, and schedule reliability.
Pack layered clothing and waterproof footwear for Denver’s December chill and potential snow; include sunglasses for high-altitude sun and a compact travel kit with essentials in case of delays. Allow extra time for TSA and ground transport—arrive 90–120 minutes before domestic departures during holiday peaks. If driving to ski areas, rent an AWD or 4WD vehicle and carry traction-relevant gear; alternatively, pre-book shuttle services to avoid winter driving stress. Keep airline apps for real-time flight alerts and set fare notifications to watch for last-minute deals. CTA: Review this checklist and prepare now to ensure a smooth December trip from Seattle (All Airports) (SEAA) to Denver (All Airports) (DENA).
Nonstop flights between Seattle (All Airports) (SEAA) and Denver (All Airports) (DENA) generally run between 2:45 and 3:15 in the air. In December airlines often add seasonal frequencies for holiday demand; expect multiple daily nonstops on Alaska Airlines and Southwest, with United and Delta offering several departures as well. Common one-stop connections include Salt Lake City (SLC), Phoenix (PHX), Minneapolis (MSP), and Dallas/Fort Worth (DFW) if you opt for a connecting itinerary to save money. For the most accurate daily schedules, check carrier timetables and consider earlier flights to reduce winter-weather risk. CTA: Check live schedules for December and book the best-fit departure time.
To score cheap flights from Seattle (All Airports) (SEAA) to Denver (All Airports) (DENA) in December, monitor prices 3–8 weeks before departure and aim for mid-week outbound flights (Tuesday or Wednesday) and Saturday returns where possible. Use fare-alerts on Google Flights or Hopper, compare low-cost carriers versus legacy airlines, and look for flash sales in late October–November. Consider refundable or flexible fares if holiday uncertainty is a concern. For last-minute savings, check early-morning departures or connecting itineraries through Salt Lake City or Phoenix, but weigh time costs. CTA: Start a price alert now to lock in cheap flights for December.
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Book your economy class flight from Seattle (Any) to Denver (Any)and save money on your travel. Compare all flight options to find the best deal for your december trip.
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Book your economy class flight from Seattle (Any) to Denver (Any)and save money on your travel. Compare all flight options to find the best deal for your december trip.
Planning a trip from Seattle (Any) to Denver (Any) in december? SlickTrip helps you find the cheapest economy class flights with our comprehensive flight comparison tool. Whether you prefer direct flights for convenience or multi-stop flights for savings, we have options for every budget and schedule.
Yes—Denver (All Airports) (DENA) serves as a primary gateway to mountain resorts such as Vail and Aspen. You can rent a vehicle (choose AWD/4WD), book private or shared shuttles, or take a connecting flight to regional airports; winter road travel times and reservation requirements make pre-booking transfers and checking avalanche/road conditions essential.
For downtown Denver, the A Line commuter rail is an affordable and reliable option, taking about 37 minutes to Union Station; shuttles and shared rides are cost-effective for Boulder and Colorado Springs. During December check schedules for holiday service adjustments; if traveling to ski resorts, shared shuttles can be cheaper than private transfers but may take longer.
