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

For as low as £652, United Airlines can have you in London Heathrow Airport from Portland, Maine in 15h 45m. The distance from Portland, Maine to London Heathrow Airport is about 3173 mi. This flight may include one or multiple stops.

In terms of precipitation, rainfall in London Heathrow Airport ranges from 40.0 - 70.0 inches per month. January is typically the wettest month, when rainfall can reach 70.0 mm. July is typically the driest time to visit London Heathrow Airport when rainfall is around 40.0 mm.

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 17.0 C. Travellers hoping to avoid the cold should look outside of January, when temperatures are typically at their lowest (around 4.0 C).

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.

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

For a flight from Portland to London Heathrow, you will be flying from Portland. Portland (PWM) is just 2.9 mi from the center of the city. Portland is the only Portland airport and it handles 0 outbound flights to London Heathrow per day. 0 airlines have flights to London Heathrow from Portland on a regular basis.

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 holiday 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.

£249+ Cheap Flights from Portland, Maine to London Heathrow Airport

Cheap flight deals from Portland to Heathrow

Enter your travel dates to find the best prices.

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 15 October 2026.

Sat 7/1114:05 -

1 stop15h 45m

Sat 14/1109:00 -

2 stops19h 21m

Deal found 13/10£652

Sat 28/1106:00 -

1 stop10h 20m

Thu 3/1206:50 -

2 stops17h 22m

Deal found 13/10£653

Sat 14/1106:00 -

2 stops20h 10m

Sat 21/1112:05 -

2 stops16h 16m

Deal found 14/10£655

Mon 26/1015:41 -

2 stops15h 09m

Fri 30/1006:50 -

2 stops16h 12m

Deal found 14/10£657

Fri 27/1108:29 -

1 stop16h 26m

Fri 4/1206:35 -

2 stops31h 30m

Deal found 13/10£658

Mon 26/1008:49 -

2 stops19h 41m

Fri 30/1009:00 -

2 stops37h 52m

Deal found 13/10£664

Mon 16/1110:50 -

2 stops21h 10m

Wed 18/1109:00 -

2 stops43h 21m

Deal found 11/10£671

Thu 12/1114:05 -

1 stop16h 35m

Thu 19/1110:50 -

1 stop17h 41m

Deal found 14/10£675

Find flight deals from Portland to Heathrow

Round-trip from	£652
One-way from	£249
Popular in	June
Cheapest in	March
Average price	£901

United Airlines
26/10-30/10
3 total stops
33h 43m total
Portland to London

Search Deals

United Airlines
28/3-31/12
2 total stops
19h 45m total
Portland to London

Search Deals

Highest demand for flights based on searches. 20% potential increase in price (£166 potential increase over avg. return price).

Search Deals

Cheapest flight prices on average. 9% potential price decrease (£57 potential savings vs. average return price).

Search Deals

Average for round-trip flights in October 2026

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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 return flight

PortlandLondon

PWM Portland - LHR London Heathrow

PWMLHR

Portland

Sun 8/11

06:30-09:30

1 stop22h 00m

London Heathrow

Wed 31/12

00:00-18:00

Nonstop0h 00m

£250

Fastest return journey

PortlandLondon

PWM Portland - LHR London Heathrow

PWMLHR

Portland

Wed 18/11

06:30-21:40

1 stop10h 10m

London Heathrow

Wed 31/12

00:00-18:00

Nonstop0h 00m

£304

PortlandLondon

PWM Portland - LHR London Heathrow

PWMLHR

Portland

Thu 19/11

06:30-21:40

1 stop10h 10m

London Heathrow

Wed 31/12

00:00-18:00

Nonstop0h 00m

£304

PortlandLondon

PWM Portland - LHR London Heathrow

PWMLHR

Portland

Sun 8/11

05:50-06:40

2 stops19h 50m

London Heathrow

Wed 31/12

00:00-18:00

Nonstop0h 00m

£307

PortlandLondon

PWM Portland - LHR London Heathrow

PWMLHR

Portland

Tue 17/11

06:27-07:50

2 stops20h 23m

London Heathrow

Wed 31/12

00:00-18:00

Nonstop0h 00m

£307

PortlandLondon

PWM Portland - LHR London Heathrow

PWMLHR

Portland

Sat 28/11

06:00-10:50

2 stops23h 50m

London Heathrow

Wed 31/12

00:00-18:00

Nonstop0h 00m

£307

PortlandLondon

PWM Portland - LHR London Heathrow

PWMLHR

Portland

Mon 23/11

08:49-06:20

1 stop16h 31m

London Heathrow

Wed 31/12

00:00-18:00

Nonstop0h 00m

£307

PortlandLondon

PWM Portland - LHR London Heathrow

PWMLHR

Portland

Sat 21/11

15:41-09:10

1 stop12h 29m

London Heathrow

Wed 31/12

00:00-18:00

Nonstop0h 00m

£345

PortlandLondon

PWM Portland - LHR London Heathrow

PWMLHR

Portland

Sun 8/11

15:10-20:05

3 stops23h 55m

London Heathrow

Wed 31/12

00:00-18:00

Nonstop0h 00m

£349

PortlandLondon

PWM Portland - LHR London Heathrow

PWMLHR

Portland

Sat 21/11

17:09-17:30

3 stops43h 21m

London Heathrow

Wed 31/12

00:00-18:00

Nonstop0h 00m

£465

Flights are sorted by cheapest return flights first.

Deals found on 14/10

Showing 1-10 of 20 resultsSorted by cheapest first

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 return 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.

Related info for your journey

What airport do you fly from for flights from Portland to London Heathrow?
For a flight from Portland to London Heathrow, you will be flying from Portland. Portland (PWM) is just 2.9 mi from the center of the city. Portland is the only Portland airport and it handles 0 outbound flights to London Heathrow per day. 0 airlines have flights to London Heathrow from Portland on a regular basis.
How long is the flight from Portland, Maine to London Heathrow Airport?
For as low as £652, United Airlines can have you in London Heathrow Airport from Portland, Maine in 15h 45m. The distance from Portland, Maine to London Heathrow Airport is about 3173 mi. This flight may include one or multiple stops.
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 holiday 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.

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Deals for Portland to Heathrow flights are sourced from 900+ travel sites when you use Cheapflights. When all flight results come back, Cheapflights lets you sort and filter flights using different criteria to choose better, like price, airport, cabin class, and plenty of other options.

Why should you use Cheapflights to find cheap flight tickets from Portland to Heathrow?

It’s simple! Cheapflights, which is free to use for everyone, saves millions of users time and money every year by helping them find the cheapest and most suitable flights from Portland to Heathrow.

Can Cheapflights find flights from Portland to Heathrow with no change fees?

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Cheap flights from Portland, Maine to London Heathrow Airport from £249

This is the cheapest retur flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 28/3. Fares are subject to change and may not be available on all flights or dates of travel.

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 15 October 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 15 October 2026.

Best flights from Portland to HeathrowDiscover carefully curated flight deals from Portland to Heathrow that have cost, travel time, and stopovers in mind to ensure you get the best travel experience. Data last updated 15 October 2026.

Discover carefully curated flight deals from Portland to Heathrow that have cost, travel time, and stopovers in mind to ensure you get the best travel experience. Data last updated 15 October 2026.

Last-minute flights from Portland to HeathrowDiscover last-minute flight deals from Portland to Heathrow. Data last updated 15 October 2026 and is based on user searches.

Discover last-minute flight deals from Portland to Heathrow. Data last updated 15 October 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 15 October 2026.

Search for one-way flight options from Portland to Heathrow. Find affordable one-way fares based on user searches. Data last updated 15 October 2026.

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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.

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?

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?

Travelling to a place near London Heathrow Airport?

Browse thousands of different options on Cheapflights for your next trip

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Alternative routes for Portland to Heathrow

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Complete your trip

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Direct flights to England

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Search flights from Portland to Heathrow by cabin class

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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 15 October 2026.

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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 15 October 2026.

Best flights from Portland to Heathrow
Discover carefully curated flight deals from Portland to Heathrow that have cost, travel time, and stopovers in mind to ensure you get the best travel experience. Data last updated 15 October 2026.

Last-minute flights from Portland to Heathrow
Discover last-minute flight deals from Portland to Heathrow. Data last updated 15 October 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 15 October 2026.