Cheap flights from Philadelphia to Seattle from R3 558

The cheapest month to fly to Seattle from Philadelphia is in January. Flight prices, which tend to average around R5 587, are often lower during this time because this is during the off-season. If you aren’t able to travel to Seattle during the month of January, then flying in February is also cheap. Prices for this month can be found on momondo for an average of R5 687.

You are more likely to see cheaper flights to Seattle from Philadelphia when booking weeks ahead of your departure date. In general, you can expect to find flights to Seattle for around R6 740 when searching weeks before you fly. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to Seattle from Philadelphia for as low as R5 936 on momondo.

Historically, on average around 18% of flights between Philadelphia and Seattle have experienced a delay on any given week. The average delay length over the past 12 months has been 159 minutes.

Generally, flights departing in the morning tend to experience fewer delays. Flights departing in the early afternoon have, in the past, seen delays more frequently in comparison.

Wednesday is statistically the day of the week that experiences the fewest delays on this flight route. Thursday has historically seen more delays on average compared to the rest of the week.

According to our data, American Airlines have had the fewest delays on this route over the last 12 months, with about 16% of their flights experiencing any sort of delay.

As of October 2026, there are 7 flights per day flying from Philadelphia to Seattle. The most common time of day flights depart is 18:00, with 52% of flights taking off in the evening.

As of October 2026, there are 52 flights per week flying from Philadelphia to Seattle. The most common day of the week flights depart is Thu, with 23% of flights taking off on this day.