How long is the flight from Portland, Maine to London Heathrow Airport?

There are many flights that can get you from Portland, Maine to London Heathrow Airport in 15h 45m. Fly via United Airlines to get the fastest option. There are 3173 mi between Portland, Maine and London Heathrow Airport.

What is the cheapest airline to fly from Portland, Maine to London Heathrow Airport round-trip?

United Airlines, at $752, was found to be the cheapest airline from Portland, Maine to London Heathrow Airport.. This flight start at 35% lower than the current average price 3 months from now.

In terms of precipitation, rainfall in London Heathrow Airport ranges from 1.6 - 2.8 inches per month. January is typically the wettest month, when rainfall can reach 2.8 in. July is typically the driest time to visit London Heathrow Airport when rainfall is around 1.6 in.

If weather is an important factor for your trip to London Heathrow Airport, use this chart to help with planning. For those seeking warmer temperatures, July is the ideal time of year to visit, when temperatures reach an average of 62.6 F. Travelers looking to avoid the cold should look outside of January, when temperatures are typically at their lowest (around 39.2 F).

What is the cheapest time of day to fly from PWM to LHR?

When flying from Portland, Maine to London Heathrow Airport, the time of day you decide to fly out makes little to no difference towards the overall price you’ll pay on tickets.

Most accurate provider : When it comes to deals on Portland, Maine-London Heathrow Airport flights, users find the pricing of Ovago to be most consistent on Cheapflights vs. Ovago Users can find the same prices on Portland, Maine-London Heathrow Airport flight deals on Cheapflights vs. Ovago >95% of the time. Price accuracy is based on data collected from Portland, Maine-London Heathrow Airport flight searches over the past month and is updated monthly.

Most trusted provider : When it comes to deals on Portland, Maine-London Heathrow Airport flights, Cheapflights users trust Ovago the most. Ovago has received a user feedback score of 3 out of 3 stars (3 being the best), meaning they have been trusted the most by Cheapflights users looking for Portland, Maine-London Heathrow Airport flight deals. Provider user feedback score is based on Cheapflights searches over the past month and is updated monthly.

What airport do you fly from for flights from Portland to London Heathrow?

Portland (PWM) is the airport you will fly out of if you book a flight from Portland to London Heathrow. You should not have trouble finding flights to London Heathrow from Portland; the airport handles an average of 0 outbound flights to London Heathrow per day. You should also have plenty of airline options to choose from since 1 airline has flights from the Portland airport to London Heathrow. It is only a 2.9 mi journey to Portland (PWM) from Portland’s city center.

Can I find deals for flights from Portland to Heathrow that include hotel bookings?

Yes. In addition to deals on Portland to Heathrow flights, Cheapflights offers vacation packages that include both flights and hotel.

How can I find direct flights from Portland to Heathrow?

After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from Portland to Heathrow.

Can I find deals for business class flights from Portland to Heathrow?

Yes. Cheapflights offers flight deals from Portland to Heathrow by cabin class. In addition to browsing deals, you can also filter by cabin class on the search results page after making a search.

$337+ Cheap Flights from Portland, ME to London Heathrow Airport

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Cheap flight deals from Portland to Heathrow

Cheapest

Best

Last-minute

One-way

Cheapest flights from Portland to Heathrow
Explore the most affordable flight options available from Portland to Heathrow. Find the lowest fares from popular airlines and budget airlines, with prices last updated on October 22, 2026.

Mon 11/163:41 pm -

2 stops19h 39m

Wed 11/189:00 am -

2 stops43h 21m

Deal found 10/17

$758

Fri 11/205:50 am -

2 stops44h 20m

Mon 11/236:50 am -

2 stops21h 31m

Deal found 10/19

$805

Mon 11/166:30 am -

1 stop10h 10m

Wed 11/1812:20 pm -

1 stop16h 23m

Deal found 10/19

$833

Sat 10/246:00 am -

1 stop9h 45m

Sat 10/318:05 am -

1 stop19h 38m

Deal found 10/17

$845

Best flights from Portland to Heathrow
Discover carefully curated flight deals from Portland to Heathrow that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated October 22, 2026.

Mon 11/162:05 pm -

1 stop15h 45m

Wed 11/189:00 am -

2 stops19h 21m

Deal found 10/17

$759

Tue 12/14:00 pm -

1 stop12h 25m

Tue 12/88:40 am -

2 stops19h 53m

Deal found 10/17

$865

Tue 12/19:12 am -

3 stops16h 58m

Tue 12/86:00 am -

3 stops22h 24m

Deal found 10/17

$882

Mon 11/165:35 am -

1 stop10h 45m

Mon 11/2312:05 pm -

2 stops16h 16m

Deal found 10/17

$863

Tue 11/1710:50 am -

1 stop18h 35m

Mon 11/239:00 am -

2 stops19h 21m

Deal found 10/20

$869

Sat 12/53:41 pm -

1 stop13h 44m

Sat 12/1212:05 pm -

2 stops16h 19m

Deal found 10/21

$869

Wed 3/246:00 am -

2 stops21h 10m

Mon 3/2910:50 am -

2 stops17h 07m

Deal found 10/20

$880

Last-minute flights from Portland to Heathrow
Discover last-minute flight deals from Portland to Heathrow. Data last updated October 22, 2026 and is based on user searches.

Sat 10/246:00 am -

1 stop9h 45m

Sat 10/318:05 am -

1 stop19h 38m

Deal found 10/17

$845

Mon 11/163:41 pm -

2 stops19h 39m

Wed 11/189:00 am -

2 stops43h 21m

Deal found 10/17

$758

Mon 11/166:30 am -

1 stop10h 10m

Wed 11/1812:20 pm -

1 stop16h 23m

Deal found 10/19

$833

Fri 11/205:50 am -

2 stops44h 20m

Mon 11/236:50 am -

2 stops21h 31m

Deal found 10/19

$805

One-way flights from Portland to Heathrow
Search for one-way flight options from Portland to Heathrow. Find affordable one-way fares based on user searches. Data last updated October 22, 2026.

Wed 11/188:49 am -

2 stops17h 21m

Wed 12/3112:00 am -

Nonstop0h 00m

Deal found 10/21

$337

Tue 11/36:01 am -

1 stop21h 59m

Wed 12/3112:00 am -

Nonstop0h 00m

Deal found 10/19

$338

Tue 11/33:41 pm -

2 stops34h 29m

Wed 12/3112:00 am -

Nonstop0h 00m

Deal found 10/19

$339

Mon 11/307:35 pm -

1 stop10h 15m

Wed 12/3112:00 am -

Nonstop0h 00m

Deal found 10/17

$341

Tue 12/14:00 pm -

2 stops16h 45m

Wed 12/3112:00 am -

Nonstop0h 00m

Deal found 10/20

$346

Wed 11/186:00 am -

2 stops20h 05m

Wed 12/3112:00 am -

Nonstop0h 00m

Deal found 10/20

$347

Tue 12/19:12 am -

3 stops16h 58m

Wed 12/3112:00 am -

Nonstop0h 00m

Deal found 10/20

$359

Wed 10/286:30 am -

1 stop11h 10m

Wed 12/3112:00 am -

Nonstop0h 00m

Deal found 10/20

$363

Find flight deals from Portland to Heathrow

Most accurate provider	Ovago 3 stars
Most trusted provider	Ovago 3 stars
Round-trip from	$758 (United Airlines)
One-way from	$337 (flygcity.se)
Popular in	June
Cheapest in	March
Average price	$1,192

Provider with most accurate pricing for Portland-London Heathrow flight deals.

Search Deals

Provider most trusted by Cheapflights users for Portland-London Heathrow flights.

Search Deals

From Portland to London Heathrow

Search Deals

One-way flight from Portland to London Heathrow

Search Deals

Highest demand for flights based on searches. 20% potential increase in price ($291 potential increase over avg. RT price).

Search Deals

Cheapest flight prices on average. 9% potential price decrease ($100 potential savings vs. average RT price).

Search Deals

Average for round-trip flights in October 2026

Search Deals

Cheapflights Fare Finder

Use the filters below to find and compare flights from Portland to London Heathrow Airport that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

Cheapest round-trip

PortlandLondon

PWM Portland - LHR London Heathrow

PWMLHR

Portland

Tue 11/3

3:41 pm-7:10 am

2 stops34h 29m

London Heathrow

Wed 12/31

12:00 am-6:00 pm

Nonstop0h 00m

$339

Quickest round-trip

PortlandLondon

PWM Portland - LHR London Heathrow

PWMLHR

Portland

Mon 11/30

7:35 pm-10:50 am

1 stop10h 15m

London Heathrow

Wed 12/31

12:00 am-6:00 pm

Nonstop0h 00m

$341

PortlandLondon

PWM Portland - LHR London Heathrow

PWMLHR

Portland

Tue 12/1

4:00 pm-9:25 am

1 stop12h 25m

London Heathrow

Wed 12/31

12:00 am-6:00 pm

Nonstop0h 00m

$341

PortlandLondon

PWM Portland - LHR London Heathrow

PWMLHR

Portland

Wed 11/18

6:00 am-7:05 am

2 stops20h 05m

London Heathrow

Wed 12/31

12:00 am-6:00 pm

Nonstop0h 00m

$347

PortlandLondon

PWM Portland - LHR London Heathrow

PWMLHR

Portland

Tue 12/1

9:12 am-7:10 am

3 stops16h 58m

London Heathrow

Wed 12/31

12:00 am-6:00 pm

Nonstop0h 00m

$359

PortlandLondon

PWM Portland - LHR London Heathrow

PWMLHR

Portland

Wed 11/18

8:49 am-7:10 am

3 stops17h 21m

London Heathrow

Wed 12/31

12:00 am-6:00 pm

Nonstop0h 00m

$395

PortlandLondon

PWM Portland - LHR London Heathrow

PWMLHR

Portland

Sun 11/1

3:40 pm-9:00 pm

2 stops48h 20m

London Heathrow

Wed 12/31

12:00 am-6:00 pm

Nonstop0h 00m

$423

PortlandLondon

PWM Portland - LHR London Heathrow

PWMLHR

Portland

Sun 11/1

11:55 am-7:05 am

1 stop14h 10m

London Heathrow

Wed 12/31

12:00 am-6:00 pm

Nonstop0h 00m

$503

PortlandLondon

PWM Portland - LHR London Heathrow

PWMLHR

Portland

Wed 10/28

8:49 am-6:30 am

3 stops17h 41m

London Heathrow

Wed 12/31

12:00 am-6:00 pm

Nonstop0h 00m

$661

PortlandLondon

PWM Portland - LHR London Heathrow

PWMLHR

Portland

Mon 11/16

2:05 pm-10:50 am

1 stop15h 45m

London Heathrow

Wed 11/18

9:00 am-11:21 pm

2 stops19h 21m

$759

Flights are sorted by cheapest round-trip flights first.

Deals found on 10/19

Showing 1-10 of 16 resultsSorted by cheapest first

Compare providers for flights from Portland to Heathrow

Use the table below to compare price accuracy, trust ratings, and cancellation policies for each provider offering flight deals from Portland to Heathrow in October.

Provider	Price Accuracy	Trust Score*
Ovago	Price Accuracy3 stars	Trust Score*3 stars
FlightHub	Price Accuracy3 stars	Trust Score*3 stars

*The Trust Score is based on feedback from users after their booking experience. It measures overall satisfaction, helping us identify issues like hidden fees, problems during the ticketing process, and the quality of customer service. This score is our best indicator of the provider's quality and reliability.

Most accurate provider: When it comes to deals on Portland, Maine-London Heathrow Airport flights, users find the pricing of Ovago to be most consistent on Cheapflights vs. Ovago Users can find the same prices on Portland, Maine-London Heathrow Airport flight deals on Cheapflights vs. Ovago >95% of the time. Price accuracy is based on data collected from Portland, Maine-London Heathrow Airport flight searches over the past month and is updated monthly.
Most trusted provider: When it comes to deals on Portland, Maine-London Heathrow Airport flights, Cheapflights users trust Ovago the most. Ovago has received a user feedback score of 3 out of 3 stars (3 being the best), meaning they have been trusted the most by Cheapflights users looking for Portland, Maine-London Heathrow Airport flight deals. Provider user feedback score is based on Cheapflights searches over the past month and is updated monthly.

Best time to book a flight from Portland to Heathrow

Have a flexible travel schedule? Discover the best time to fly to Heathrow from Portland with our price prediction graph.

PWM-LHR

Estimated round-trip price

Rates are based on past data. Find the cheapest month and day to book your flight based on your travel requirements, then search for cheap deals.

Reviews of airlines servicing Heathrow

Read through reviews of airlines operating flights from Portland to London Heathrow Airport, such as United Airlines. Reviews also offer insight into each airline's entertainment options, comfort, food, crew/service, and boarding process.

United Airlines

7.3

Good

10,392 reviews

Reviews

1 / 20

8.0

Excellent

Asha,Sep 2026

LGA - IAH

The flight was on time and boardi g was very organized and timely. Snacks are awful and having one little glass of juice was terrible. Fortunately, I had my water to keep me hydrated.

United Airlines

7.3

Good

10,392 reviews

United Airlines

7.3

Good

10,392 reviews

Reviews

1 / 20

8.0

Excellent

Asha,Sep 2026

LGA - IAH

The flight was on time and boardi g was very organized and timely. Snacks are awful and having one little glass of juice was terrible. Fortunately, I had my water to keep me hydrated.

Related info for your journey

What airport do you fly from for flights from Portland to London Heathrow?
Portland (PWM) is the airport you will fly out of if you book a flight from Portland to London Heathrow. You should not have trouble finding flights to London Heathrow from Portland; the airport handles an average of 0 outbound flights to London Heathrow per day. You should also have plenty of airline options to choose from since 1 airline has flights from the Portland airport to London Heathrow. It is only a 2.9 mi journey to Portland (PWM) from Portland’s city center.
How long is the flight from Portland, Maine to London Heathrow Airport?
There are many flights that can get you from Portland, Maine to London Heathrow Airport in 15h 45m. Fly via United Airlines to get the fastest option. There are 3173 mi between Portland, Maine and London Heathrow Airport.
What is the cheapest airline to fly from Portland, Maine to London Heathrow Airport round-trip?
United Airlines, at $752, was found to be the cheapest airline from Portland, Maine to London Heathrow Airport.. This flight start at 35% lower than the current average price 3 months from now.
Can I find deals for flights from Portland to Heathrow that include hotel bookings?
Yes. In addition to deals on Portland to Heathrow flights, Cheapflights offers vacation packages that include both flights and hotel.
How can I find direct flights from Portland to Heathrow?
After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from Portland to Heathrow.
Can I find deals for business class flights from Portland to Heathrow?
Yes. Cheapflights offers flight deals from Portland to Heathrow by cabin class. In addition to browsing deals, you can also filter by cabin class on the search results page after making a search.

See more FAQs

Ilford

Dorking

Hounslow

Gatwick

Wembley

Harrow

Southend-on-Sea

Basingstoke

Watford

Northampton

Dartford

Winchester

Croydon

Chipping Norton

Kingston upon Thames

Slough

Eastbourne

Stansted

Sutton

Luton

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Bangor to Heathrow flights

Top airline flying from Portland to Heathrow

Airline	Cheapest	Average	Flexibility	On-time
United Airlines	Cheapest$752	Average$1,192	FlexibilityNo cancel fee	On-time69%

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$337+ Cheap flights from Portland, ME (PWM) to Heathrow (LHR)

This is the cheapest round-trip flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 11/18. Fares are subject to change and may not be available on all flights or dates of travel.

Find cheap flights from Portland to Heathrow with Cheapflights

1. Tell us where you want to go

2. Select your favorite providers

3. Compare prices and book

Cheap flight deals from Portland to Heathrow

Cheapest flights from Portland to HeathrowExplore the most affordable flight options available from Portland to Heathrow. Find the lowest fares from popular airlines and budget airlines, with prices last updated on October 22, 2026.

Explore the most affordable flight options available from Portland to Heathrow. Find the lowest fares from popular airlines and budget airlines, with prices last updated on October 22, 2026.

Best flights from Portland to HeathrowDiscover carefully curated flight deals from Portland to Heathrow that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated October 22, 2026.

Discover carefully curated flight deals from Portland to Heathrow that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated October 22, 2026.

Last-minute flights from Portland to HeathrowDiscover last-minute flight deals from Portland to Heathrow. Data last updated October 22, 2026 and is based on user searches.

Discover last-minute flight deals from Portland to Heathrow. Data last updated October 22, 2026 and is based on user searches.

One-way flights from Portland to HeathrowSearch for one-way flight options from Portland to Heathrow. Find affordable one-way fares based on user searches. Data last updated October 22, 2026.

Search for one-way flight options from Portland to Heathrow. Find affordable one-way fares based on user searches. Data last updated October 22, 2026.

Find flight deals from Portland to Heathrow

Most accurate provider

Most trusted provider

Round-trip from

One-way from

Popular in

Cheapest in

Average price

Cheapflights Fare Finder

Use the filters below to find and compare flights from Portland to London Heathrow Airport that are best for you.

Compare providers for flights from Portland to Heathrow

Provider information is updated monthly. Please note that these providers often have deals for this flight, but the availability may vary on a day-by-day basis on Cheapflights.

Use the table below to compare price accuracy, trust ratings, and cancellation policies for each provider offering flight deals from Portland to Heathrow in October.

Best time to book a flight from Portland to Heathrow

Have a flexible travel schedule? Discover the best time to fly to Heathrow from Portland with our price prediction graph.

Reviews of airlines servicing Heathrow

Read through reviews of airlines operating flights from Portland to London Heathrow Airport, such as United Airlines. Reviews also offer insight into each airline's entertainment options, comfort, food, crew/service, and boarding process.

Related info for your journey

What airport do you fly from for flights from Portland to London Heathrow?

How long is the flight from Portland, Maine to London Heathrow Airport?

What is the cheapest airline to fly from Portland, Maine to London Heathrow Airport round-trip?

Can I find deals for flights from Portland to Heathrow that include hotel bookings?

How can I find direct flights from Portland to Heathrow?

Can I find deals for business class flights from Portland to Heathrow?

Traveling to a place near London Heathrow Airport?

Browse thousands of different options on Cheapflights for your next trip

Toggle through the tabs below to find thousands of options on Cheapflights for your next trip.

Alternative routes for Portland to Heathrow

See prices for flight routes from nearby airports that may be better suited for you.

Complete your trip

Complete your trip to Heathrow by adding a car rental and/or hotel reservation to your travel itinerary.

Search flights from Portland to Heathrow by cabin class

Find flights from Portland to Heathrow, based on your preferred cabin class, be it economy, premium economy, business, or first class.

Other flights to Heathrow

Explore flights to Heathrow departing from other origins. Flights are based on user searches made on Cheapflights and were last updated on October 22, 2026.

Portland and Heathrow flights

Browse other Portland and Heathrow flight options. Last updated on October 22, 2026.

Other flights from Portland

Browse through other flights departing from Portland. Flights are based on user searches made on Cheapflights and were last updated on October 22, 2026.

Popular flight searches

Check out other popular destinations found by fellow travelers in 2026

Top airline flying from Portland to Heathrow

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Cheapest flights from Portland to Heathrow
Explore the most affordable flight options available from Portland to Heathrow. Find the lowest fares from popular airlines and budget airlines, with prices last updated on October 22, 2026.

Best flights from Portland to Heathrow
Discover carefully curated flight deals from Portland to Heathrow that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated October 22, 2026.

Last-minute flights from Portland to Heathrow
Discover last-minute flight deals from Portland to Heathrow. Data last updated October 22, 2026 and is based on user searches.

One-way flights from Portland to Heathrow
Search for one-way flight options from Portland to Heathrow. Find affordable one-way fares based on user searches. Data last updated October 22, 2026.