Which airline has the best punctuality record on Philadelphia to Seattle flights?

Over the past year, American Airlines have had the lowest number of delays on this route, with just 16% of flights being delayed.

What day of the week experiences the fewest flight delays on this route?

Wednesday tends to have the lowest number of delays on this route, whereas Thursday has historically faced a higher average of delays compared to other days of the week.

What is the most punctual flight time for Philadelphia to Seattle flights?

Historically, flights departing in the morning are less likely to be delayed, whereas flights leaving in the early afternoon tend to experience delays more often.

How often are flights from Philadelphia to Seattle delayed?

About 18% of weekly flights between Philadelphia and Seattle have experienced delays in the past year, with the average delay time being 159 minutes.

How long is the flight from Philadelphia to Seattle?

For as low as £322, United Airlines can have you in Seattle from Philadelphia in 8h 35m. Philadelphia and Seattle are separated by a distance of 2370 mi. Both multi-stop and direct flights can be found to your destination and back.

Weekly flight availability from Philadelphia to Seattle

The most flights from PHL to SEA are scheduled on a Monday (11 on average). You will have fewer flight options on Tuesday, which is when the least amount of flights are scheduled (4 on average).

In terms of precipitation, rainfall in Seattle ranges from 18.0 - 168.0 inches per month. November is typically the wettest month, when rainfall can reach 168.0 mm. July is typically the driest time to visit Seattle when rainfall is around 18.0 mm.

If weather is an important factor for your trip to Seattle, 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 19.0 C. Travellers hoping to avoid the cold should look outside of December, when temperatures are typically at their lowest (around 5.0 C).

What are the most reliable airlines from Philadelphia to Seattle?

Before booking your flight to Seattle from Philadelphia, check out the most reliable airlines to get you to your destination on time: American Airlines (88%), Finnair (88%), British Airways( 85%).

Can I find deals for flights from Philadelphia to Seattle that include hotel bookings?

Yes. In addition to deals on Philadelphia to Seattle flights, Cheapflights offers holiday packages that include both flights and hotel.

How can I find direct flights from Philadelphia to Seattle?

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

Can I find deals for business class flights from Philadelphia to Seattle?

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

£172+ Cheap Flights from Philadelphia to Seattle

Cheap flight deals from Philadelphia to Seattle

Enter your travel dates to find the best prices.

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Cheapest flights from Philadelphia to Seattle
Explore the most affordable flight options available from Philadelphia to Seattle. Find the lowest fares from popular airlines and budget airlines, with prices last updated on 11 November 2026.

Fri 25/1207:02 -

Nonstop6h 27m

Fri 1/109:18 -

Nonstop5h 07m

Deal found 10/11£304

Fri 25/1207:02 -

Nonstop6h 27m

Tue 29/1221:33 -

Nonstop5h 09m

Deal found 10/11£304

Tue 15/1218:11 -

Nonstop6h 42m

Sat 26/1221:33 -

Nonstop5h 09m

Deal found 11/11£311

Wed 16/1207:00 -

Nonstop6h 28m

Mon 28/1221:33 -

Nonstop5h 09m

Deal found 11/11£312

Mon 14/1218:11 -

Nonstop6h 42m

Mon 28/1221:33 -

Nonstop5h 09m

Deal found 11/11£313

Mon 14/1206:24 -

1 stop8h 20m

Thu 17/1219:10 -

1 stop7h 21m

Deal found 9/11£315

Sat 5/1209:20 -

1 stop10h 03m

Wed 9/1208:30 -

1 stop8h 01m

Deal found 9/11£316

Sat 5/1209:20 -

1 stop10h 03m

Tue 8/1210:48 -

1 stop7h 51m

Deal found 9/11£316

Fri 18/1215:39 -

1 stop11h 16m

Sun 17/108:00 -

1 stop8h 57m

Deal found 10/11£319

Tue 8/1209:20 -

1 stop10h 02m

Tue 15/1207:00 -

1 stop7h 57m

Deal found 10/11£319

Tue 8/1206:20 -

1 stop11h 16m

Wed 9/1206:00 -

1 stop9h 19m

Deal found 8/11£320

Find flight deals from Philadelphia to Seattle

Round-trip from	£304
One-way from	£172
Popular in	August
Cheapest in	January
Average price	£337

Alaska Airlines
11/12-12/12
Nonstop
11h 47m total
Philadelphia to Seattle

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Southwest
7/12-31/12
1 total stop
8h 20m total
Philadelphia to Seattle

Search Deals

Highest demand for flights based on searches. 7% potential increase in price (£19 potential increase over avg. return price).

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Cheapest flight prices on average. 1% potential price decrease (£4 potential savings vs. average return price).

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Average for round-trip flights in November 2026

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Cheapflights Fare Finder

Use the filters below to find and compare flights from Philadelphia to Seattle that are best for you.

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Route

Depart

Return

Price

Cheapest return flight

PhiladelphiaSeattle

PHL Philadelphia - SEA Seattle/Tacoma Intl

PHLSEA

Philadelphia

Wed 18/11

13:25-23:35

1 stop13h 10m

Seattle/Tacoma Intl

Wed 31/12

00:00-03:00

Nonstop0h 00m

£193

PhiladelphiaSeattle

PHL Philadelphia - SEA Seattle/Tacoma Intl

PHLSEA

Philadelphia

Sat 21/11

16:15-01:35

2 stops12h 20m

Seattle/Tacoma Intl

Wed 31/12

00:00-03:00

Nonstop0h 00m

£193

PhiladelphiaSeattle

PHL Philadelphia - SEA Seattle/Tacoma Intl

PHLSEA

Philadelphia

Mon 29/3

06:15-12:30

1 stop9h 15m

Seattle/Tacoma Intl

Wed 31/12

00:00-03:00

Nonstop0h 00m

£200

PhiladelphiaSeattle

PHL Philadelphia - SEA Seattle/Tacoma Intl

PHLSEA

Philadelphia

Fri 4/12

18:11-21:53

Nonstop6h 42m

Seattle/Tacoma Intl

Wed 31/12

00:00-03:00

Nonstop0h 00m

£201

PhiladelphiaSeattle

PHL Philadelphia - SEA Seattle/Tacoma Intl

PHLSEA

Philadelphia

Tue 22/12

14:15-23:10

2 stops11h 55m

Seattle/Tacoma Intl

Wed 31/12

00:00-03:00

Nonstop0h 00m

£201

PhiladelphiaSeattle

PHL Philadelphia - SEA Seattle/Tacoma Intl

PHLSEA

Philadelphia

Mon 4/1

14:30-23:05

2 stops11h 35m

Seattle/Tacoma Intl

Wed 31/12

00:00-03:00

Nonstop0h 00m

£201

PhiladelphiaSeattle

PHL Philadelphia - SEA Seattle/Tacoma Intl

PHLSEA

Philadelphia

Sat 27/3

07:00-10:09

Nonstop6h 09m

Seattle/Tacoma Intl

Wed 31/12

00:00-03:00

Nonstop0h 00m

£201

PhiladelphiaSeattle

PHL Philadelphia - SEA Seattle/Tacoma Intl

PHLSEA

Philadelphia

Sun 6/12

06:00-11:10

1 stop8h 10m

Seattle/Tacoma Intl

Wed 31/12

00:00-03:00

Nonstop0h 00m

£208

PhiladelphiaSeattle

PHL Philadelphia - SEA Seattle/Tacoma Intl

PHLSEA

Philadelphia

Wed 10/3

10:15-00:49

3 stops17h 34m

Seattle/Tacoma Intl

Wed 31/12

00:00-03:00

Nonstop0h 00m

£216

PhiladelphiaSeattle

PHL Philadelphia - SEA Seattle/Tacoma Intl

PHLSEA

Philadelphia

Thu 19/11

13:25-22:20

2 stops11h 55m

Seattle/Tacoma Intl

Wed 31/12

00:00-03:00

Nonstop0h 00m

£242

Flights are sorted by cheapest return flights first.

Deals found on 8/11

Showing 1-10 of 23 resultsSorted by cheapest first

Best time to book a flight from Philadelphia to Seattle

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

PHL-SEA

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.

Cheapflights Insights

Everything you need to know about your flight from Philadelphia to Seattle

Prices

Airlines

Delays

How far ahead should I book a flight from Philadelphia to Seattle?

Booking 70 days in advance of your planned departure date is, on average, the best time to get cheap flights from Philadelphia to Seattle. The general trend is that the closer you book to the departure date, the more expensive your flight will be.

What is the cheapest month to book a flight from Philadelphia to Seattle?

Currently, January is the cheapest month in which you can book a flight from Philadelphia to Seattle (average of £251). Flying from Philadelphia to Seattle in August is currently the most expensive (average of £350). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

What is the cheapest time of day to fly from PHL to SEA?

When flying from Philadelphia to Seattle, the time of day you decide to fly out makes little to no difference towards the overall price you’ll pay on tickets.

How much does it cost for a return flight from Philadelphia to Seattle?

Airfare is typical for this route at the moment.

Philadelphia to Seattle flights typically cost between £296 and £431 in December.
The cheapest return price found within the last 5 days was £304 on Alaska Airlines (25 Dec–1 Jan).

Related info for your journey

How long is the flight from Philadelphia to Seattle?
For as low as £322, United Airlines can have you in Seattle from Philadelphia in 8h 35m. Philadelphia and Seattle are separated by a distance of 2370 mi. Both multi-stop and direct flights can be found to your destination and back.
What are the most reliable airlines from Philadelphia to Seattle?
Before booking your flight to Seattle from Philadelphia, check out the most reliable airlines to get you to your destination on time: American Airlines (88%), Finnair (88%), British Airways( 85%).
Can I find deals for flights from Philadelphia to Seattle that include hotel bookings?
Yes. In addition to deals on Philadelphia to Seattle flights, Cheapflights offers holiday packages that include both flights and hotel.
How can I find direct flights from Philadelphia to Seattle?
After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from Philadelphia to Seattle.
Can I find deals for business class flights from Philadelphia to Seattle?
Yes. Cheapflights offers flight deals from Philadelphia to Seattle by cabin class. In addition to browsing deals, you can also filter by cabin class on the search results page after making a search.
What is the cheapest month to book a flight from Philadelphia to Seattle?
Currently, January is the cheapest month in which you can book a flight from Philadelphia to Seattle (average of £251). Flying from Philadelphia to Seattle in August is currently the most expensive (average of £350). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

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Deals for Philadelphia to Seattle 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 Philadelphia to Seattle?

Cheapflights helps you find that perfect flight to Seattle from Philadelphia by searching from hundreds of airlines and agencies you know and love. We are also free to use, in case you were wondering!

Can Cheapflights find flights from Philadelphia to Seattle with no change fees?

Need flexible booking options for your flight to Seattle from Philadelphia? Don’t worry, Cheapflights have you covered. Use our search filter to only show flights with no change fees.

Can Cheapflights notify me if prices for flights from Philadelphia to Seattle become cheaper?

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Cheap flights from Philadelphia to Seattle from £172

This is the cheapest retur flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 7/12. Fares are subject to change and may not be available on all flights or dates of travel.

Cheap flight deals from Philadelphia to Seattle

Cheapest flights from Philadelphia to SeattleExplore the most affordable flight options available from Philadelphia to Seattle. Find the lowest fares from popular airlines and budget airlines, with prices last updated on 11 November 2026.

Explore the most affordable flight options available from Philadelphia to Seattle. Find the lowest fares from popular airlines and budget airlines, with prices last updated on 11 November 2026.

Best flights from Philadelphia to SeattleDiscover carefully curated flight deals from Philadelphia to Seattle that have cost, travel time, and stopovers in mind to ensure you get the best travel experience. Data last updated 11 November 2026.

Discover carefully curated flight deals from Philadelphia to Seattle that have cost, travel time, and stopovers in mind to ensure you get the best travel experience. Data last updated 11 November 2026.

Direct flights from Philadelphia to SeattleExplore direct flight options from Philadelphia to Seattle based on user searches, and compare prices and availability for your desired travel dates. Data last updated 11 November 2026.

Explore direct flight options from Philadelphia to Seattle based on user searches, and compare prices and availability for your desired travel dates. Data last updated 11 November 2026.

Last-minute flights from Philadelphia to SeattleDiscover last-minute flight deals from Philadelphia to Seattle. Data last updated 11 November 2026 and is based on user searches.

Discover last-minute flight deals from Philadelphia to Seattle. Data last updated 11 November 2026 and is based on user searches.

One-way flights from Philadelphia to SeattleSearch for one-way flight options from Philadelphia to Seattle. Find affordable one-way fares based on user searches. Data last updated 11 November 2026.

Search for one-way flight options from Philadelphia to Seattle. Find affordable one-way fares based on user searches. Data last updated 11 November 2026.

Find flight deals from Philadelphia to Seattle

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Use the filters below to find and compare flights from Philadelphia to Seattle that are best for you.

Best time to book a flight from Philadelphia to Seattle

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

Cheapflights Insights

How far ahead should I book a flight from Philadelphia to Seattle?

Booking 70 days in advance of your planned departure date is, on average, the best time to get cheap flights from Philadelphia to Seattle. The general trend is that the closer you book to the departure date, the more expensive your flight will be.

What is the cheapest month to book a flight from Philadelphia to Seattle?

What is the cheapest time of day to fly from PHL to SEA?

When flying from Philadelphia to Seattle, the time of day you decide to fly out makes little to no difference towards the overall price you’ll pay on tickets.

How much does it cost for a return flight from Philadelphia to Seattle?

Airfare is typical for this route at the moment.

Philadelphia to Seattle flights typically cost between £296 and £431 in December.The cheapest return price found within the last 5 days was £304 on Alaska Airlines (25 Dec–1 Jan).

Weekly flight availability from Philadelphia to Seattle

The most flights from PHL to SEA are scheduled on a Monday (11 on average). You will have fewer flight options on Tuesday, which is when the least amount of flights are scheduled (4 on average).

How often are flights from Philadelphia to Seattle delayed?

About 18% of weekly flights between Philadelphia and Seattle have experienced delays in the past year, with the average delay time being 159 minutes.

What is the most punctual flight time for Philadelphia to Seattle flights?

Historically, flights departing in the morning are less likely to be delayed, whereas flights leaving in the early afternoon tend to experience delays more often.

What day of the week experiences the fewest flight delays on this route?

Wednesday tends to have the lowest number of delays on this route, whereas Thursday has historically faced a higher average of delays compared to other days of the week.

Which airline has the best punctuality record on Philadelphia to Seattle flights?

Over the past year, American Airlines have had the lowest number of delays on this route, with just 16% of flights being delayed.

Related info for your journey

How long is the flight from Philadelphia to Seattle?

What are the most reliable airlines from Philadelphia to Seattle?

Can I find deals for flights from Philadelphia to Seattle that include hotel bookings?

How can I find direct flights from Philadelphia to Seattle?

Can I find deals for business class flights from Philadelphia to Seattle?

What is the cheapest month to book a flight from Philadelphia to Seattle?

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Philadelphia and Seattle flights

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Can Cheapflights notify me if prices for flights from Philadelphia to Seattle become cheaper?

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Cheapest flights from Philadelphia to Seattle
Explore the most affordable flight options available from Philadelphia to Seattle. Find the lowest fares from popular airlines and budget airlines, with prices last updated on 11 November 2026.

Best flights from Philadelphia to Seattle
Discover carefully curated flight deals from Philadelphia to Seattle that have cost, travel time, and stopovers in mind to ensure you get the best travel experience. Data last updated 11 November 2026.

Direct flights from Philadelphia to Seattle
Explore direct flight options from Philadelphia to Seattle based on user searches, and compare prices and availability for your desired travel dates. Data last updated 11 November 2026.

Last-minute flights from Philadelphia to Seattle
Discover last-minute flight deals from Philadelphia to Seattle. Data last updated 11 November 2026 and is based on user searches.

One-way flights from Philadelphia to Seattle
Search for one-way flight options from Philadelphia to Seattle. Find affordable one-way fares based on user searches. Data last updated 11 November 2026.

Philadelphia to Seattle flights typically cost between £296 and £431 in December.
The cheapest return price found within the last 5 days was £304 on Alaska Airlines (25 Dec–1 Jan).