Submit feedbackComplete travel information for your December journey
Nonstop flights from Denver International Airport (DEN) to London Heathrow Airport (LHR) in December typically take about 8 hours 30 minutes to 9 hours depending on wind and routing. Seasonal jet streams and winter weather can add variability, so allow extra time for potential delays and check your airline's real-time updates before departure.
In December, major carriers operating DEN–LHR include United Airlines and British Airways for nonstop services, with many one-stop options offered by carriers such as Lufthansa, Air Canada and Icelandair via their hubs. For the best schedule and fare options during the holiday season, compare nonstop and single-connection itineraries and book early to secure preferred departure times.
Baggage allowances vary by airline and fare class: typical international checked baggage limits run 1–2 pieces (23–32 kg/50–70 lbs each) and carry-on allowances usually permit one larger bag plus a personal item. For December holiday travel, verify your airline's specific rules and fees, as premium fares often include higher allowances while basic economy may restrict carry-on or charge fees.
December in Denver can bring snow and ice that occasionally delay or cancel flights; London weather is milder but can be foggy or rainy. Monitor forecasts from the National Weather Service and check airline notifications—arrive early for winter check-in and allow extra time for ground transportation to Denver International Airport (DEN).
Denver International Airport (DEN) offers the A Line commuter rail to Union Station, airport shuttles, rideshares, taxis, and rental cars; shuttle and rail schedules may be adjusted during holidays. Nearby major Colorado destinations commonly accessed include Colorado Springs, Boulder, Fort Collins, Aspen and Vail—book transfers in advance during December ski season to secure space.
Most airline lounges, restaurants and essential services at Denver International Airport (DEN) remain open through December holidays, although hours can vary on Christmas Day and New Year's Day. Check the Denver International Airport official website and your airline for holiday-hour notices and reserve lounge access or dining in advance where possible.
Arrivals at London Heathrow Airport (LHR) in December often involve longer passport control and baggage wait times due to higher seasonal traffic. Allow extra time for immigration, and consider using eGates if eligible; pre-booked airport transfers to London, Windsor, Reading or Oxford are recommended to avoid lines during peak holiday periods.
From London Heathrow Airport (LHR) you can take the Heathrow Express to Paddington (fastest), the Elizabeth Line for direct access across London, National Express coaches to regional cities, taxis, rideshares, and pre-booked transfers. In December, book the Heathrow Express or car services early and expect possible rail schedule changes for holiday engineering work.
Most U.S. citizens traveling from Denver International Airport (DEN) to London Heathrow Airport (LHR) for short tourist or business stays do not need a visa for visits up to six months, but passport validity and entry rules should be checked before travel. For other nationalities or longer stays, verify visa requirements well before December travel through the UK government website or your local consulate.
December travelers from Denver International Airport (DEN) arriving at London Heathrow Airport (LHR) can enjoy London’s Christmas markets (Southbank, Hyde Park Winter Wonderland), festive light displays in central London, and New Year’s Eve events along the Thames. Nearby Windsor hosts seasonal events at Windsor Castle, and Oxford offers winter tours and holiday markets. Plan for crowded attractions and pre-book tickets for popular events.
The best time to fly from Denver International Airport (DEN) to London Heathrow Airport (LHR) in December is mid-week (Tuesday–Thursday) outside peak holiday travel windows. Early December generally has lower demand and better fares than the period immediately before Christmas and the week after. Overnight departures from DEN are advantageous for maximizing daytime arrival in London, and booking several weeks ahead will help you secure favorable prices.
Nonstop flights from Denver International Airport (DEN) to London Heathrow Airport (LHR) offer the fastest and most convenient option, typically around 8.5–9 hours. Connecting flights can be cheaper but add travel time and the risk of missed connections—especially in December when weather disruptions are more likely. If price is your priority, look for single-connection routings through major hubs like Frankfurt, Toronto or Reykjavik; if reliability and time are critical, choose nonstop carriers such as United or British Airways.
United Airlines and British Airways typically operate nonstop DEN–LHR services in December, offering comparable flight times and premium cabin options. British Airways often provides premium economy and strong UK connectivity; United can offer MileagePlus benefits and U.S.-centric schedules. One-stop options (Lufthansa via Frankfurt, Air Canada via Toronto, Icelandair via Reykjavik) may be cheaper but increase travel time. Compare seat width, onboard service, baggage inclusions, and loyalty benefits to choose the best carrier for your December trip.
Packing layers, winter footwear, and a compact umbrella are essential for December travel from Denver to London. Prepare for snowy conditions around Denver International Airport (DEN) and rain or fog in London, and allow extra time for check-in, security, and immigration. Consider travel insurance for weather-related cancellations, enroll in airline notification systems, and keep digital and printed copies of important travel documents. If you’re connecting to Colorado ski destinations (Aspen, Vail) or visiting London-area holiday sites (Windsor, Oxford), book transfers and accommodations well in advance.
Nonstop flight time between Denver International Airport (DEN) and London Heathrow Airport (LHR) averages 8 hours 30 minutes to 9 hours, depending on winds and routing. Most carriers operate evening departures from Denver that arrive in London the following morning local time—maximizing daytime in the destination. If you choose a one-stop routing, total travel time typically ranges 11–16 hours, depending on connection length and routing hub. Allow for Daylight Saving Time differences and set your devices to local time to reduce jet lag.
To find cheap December flights from Denver International Airport (DEN) to London Heathrow Airport (LHR), start searching 8–12 weeks in advance and monitor mid-week departures and returns. Use fare alerts, flexible date tools, and alternate nearby airports for connections—sometimes routing through major European hubs yields savings. Consider one-stop itineraries via Frankfurt, Toronto, or Reykjavik for lower fares compared with nonstop services by United or British Airways. During December, lock fares quickly when you see a deal, as holiday demand can cause rapid increases.
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Book your economy class flight from Denver (DEN) to London (LHR)and save money on your travel. Compare all flight options to find the best deal for your december trip.
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As of December this year, the UK does not have routine mandatory COVID-19 entry testing for most travelers, but requirements can change—check official UK government guidance before you fly. Carry proof of vaccination or test results if you are traveling under special circumstances, and keep health insurance and contact details handy.
London Heathrow Airport (LHR) provides easy access to central London, Windsor (castle and holiday markets), Oxford (historic university city), Reading (business hub), and Brighton (coastal getaway). December travelers often combine their London stay with day trips to Windsor's festive events and Oxford's seasonal tours.
Major lounges, duty-free shops and restaurants at London Heathrow Airport (LHR) typically operate through December with extended hours during peak days, but some outlets may reduce hours on Christmas Day. For a smoother arrival, pre-book lounge access and check Heathrow's retail and hospitality pages for holiday opening times.
