
Most accurate provider | FlightHub 3 stars |
|---|---|
Most trusted provider | FlightHub 3 stars |
Round-trip from | $329 (Delta) |
One-way from | $165 (Delta) |
Popular in | December |
Cheapest in | October |
Average price | $472 |
Good round-trip deal | $355 or less |
Good one-way deal | $195 or less |
Fly from
Fly to
Route
Depart
Return
PhiladelphiaSeattle
PHL - SEA
PHLSEA
Philadelphia
Sat 7/4
6:45 pm-9:59 pm
Nonstop6h 14m
Seattle/Tacoma Intl
Fri 7/10
9:20 pm-5:29 am
Nonstop5h 09m
PhiladelphiaSeattle
PHL - SEA
PHLSEA
Philadelphia
Tue 8/25
7:05 am-10:01 am
Nonstop5h 56m
Seattle/Tacoma Intl
Thu 9/10
9:50 pm-6:05 am
Nonstop5h 15m
PhiladelphiaSeattle
PHL - SEA
PHLSEA
Philadelphia
Thu 8/27
7:05 am-10:01 am
Nonstop5h 56m
Seattle/Tacoma Intl
Sun 9/6
9:30 pm-5:50 am
Nonstop5h 20m
PhiladelphiaSeattle
PHL - SEA
PHLSEA
Philadelphia
Mon 7/13
7:33 am-10:32 am
Nonstop5h 59m
Seattle/Tacoma Intl
Wed 7/22
10:02 pm-6:13 am
Nonstop5h 11m
PhiladelphiaSeattle
PHL - SEA
PHLSEA
Philadelphia
Mon 8/10
6:05 pm-11:30 pm
1 stop8h 25m
Seattle/Tacoma Intl
Thu 8/13
5:15 am-5:55 pm
1 stop9h 40m
PhiladelphiaSeattle
PHL - SEA
PHLSEA
Philadelphia
Fri 8/21
4:48 pm-10:39 pm
1 stop8h 51m
Seattle/Tacoma Intl
Mon 8/31
9:27 pm-5:40 am
Nonstop5h 13m
PhiladelphiaSeattle
PHL - SEA
PHLSEA
Philadelphia
Tue 8/18
7:05 am-10:01 am
Nonstop5h 56m
Seattle/Tacoma Intl
Mon 8/24
7:50 pm-6:05 am
1 stop7h 15m
PhiladelphiaSeattle
PHL - SEA
PHLSEA
Philadelphia
Thu 8/20
7:05 am-10:01 am
Nonstop5h 56m
Seattle/Tacoma Intl
Thu 8/27
6:09 pm-6:05 am
1 stop8h 56m
PhiladelphiaSeattle
PHL - SEA
PHLSEA
Philadelphia
Mon 9/7
7:00 pm-11:59 pm
1 stop7h 59m
Seattle/Tacoma Intl
Tue 9/8
9:50 pm-6:05 am
Nonstop5h 15m
PhiladelphiaSeattle
PHL - SEA
PHLSEA
Philadelphia
Wed 8/19
4:48 pm-10:39 pm
1 stop8h 51m
Seattle/Tacoma Intl
Wed 9/2
9:27 pm-5:40 am
Nonstop5h 13m
| Provider | Price Accuracy | Trust Score* |
|---|---|---|
| Price Accuracy1 star | Trust Score*3 stars | |
| Price Accuracy3 stars | Trust Score*3 stars | |
| Price Accuracy3 stars | Trust Score*3 stars | |
| Price Accuracy- | Trust Score*1 star | |
| Price Accuracy2 stars | Trust Score*3 stars | |
| Price Accuracy1 star | Trust Score*3 stars | |
| Price Accuracy1 star | Trust Score*3 stars |
The best time to book flights from Philadelphia to Seattle is 70 days before your desired departure date. The cost of your flight will likely increase significantly if you book two weeks in advance of your flight.
Currently, October is the cheapest month in which you can book a flight from Philadelphia to Seattle (average of $317). Flying from Philadelphia to Seattle in December is currently the most expensive (average of $477). 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.
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.
About 20% of weekly flights between Philadelphia and Seattle have experienced delays in the past year, with the average delay time being 148 minutes.
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.
Tuesday tends to have the lowest number of delays on this route, whereas Friday has historically faced a higher average of delays compared to other days of the week.
Over the last year, American Airlines have had the lowest number of delays on this route, with just 15% of flights being delayed.
Denver (DEN) – chosen by Cheapflights users on 67% of 1-stop itineraries from Philadelphia to Seattle on Cheapflights.
Denver (DEN) is the most affordable 1-stop option, with an average round-trip price of $208.
Flights via Chicago (ORD) have the shortest average one-way travel time for 1-stop routes: 8h 04m.
Flights via Chicago (ORD) offer the fastest connection on this route, with an average layover time of 1h 05m.
Boarding
Crew
Entertainment
Overall
Comfort
Food
Reviews
Anonymous,Jun 2026
RDU - SEA
Boarding
Crew
Entertainment
Overall
Comfort
Food
Reviews
Anonymous,Jun 2026
RDU - SEA
Boarding
Crew
Entertainment
Overall
Comfort
Food
Reviews
Anonymous,Jun 2026
RDU - SEA
Boarding
Crew
Entertainment
Overall
Comfort
Food
Reviews
Anonymous,Jun 2026
RDU - SEA
Boarding
Crew
Entertainment
Overall
Comfort
Food
Reviews
Anonymous,Jun 2026
RDU - SEA
Boarding
Crew
Entertainment
Overall
Comfort
Food
Reviews
Anonymous,Jun 2026
RDU - SEA
| Airline | Cheapest | Average | Flexibility | On-time |
|---|---|---|---|---|
| Cheapest$134 | Average$298 | FlexibilityNo cancel fee | On-time62% | |
| Cheapest$163 | Average$422 | FlexibilityNo cancel fee | On-time85% | |
| Cheapest$198 | Average$396 | FlexibilityNo cancel fee | On-time63% | |
| Cheapest$200 | Average$376 | FlexibilityNo cancel fee | On-timeN/A | |
| Cheapest$238 | Average$420 | FlexibilityNo cancel fee | On-time75% | |
| Cheapest$260 | Average$422 | FlexibilityNo cancel fee | On-time69% | |
| Cheapest$270 | Average$432 | FlexibilityNo cancel fee | On-time71% |