The cheapest times to fly from SEA to STL are
- January 1st to February 25th (except the week of February 12th)
- April 16th to May 6th
- August 13th to November 18th
based on data collected exclusively by Champion Traveler across tens of millions of flights. Among all the dates above, the very cheapest time to fly from SEA to STL is late October. Prices can be as high as $1026 for Sunday flights during late July, or as low as $255 for Tuesday flights around late October.
When to Fly to St. Louis
Flying from Seattle, WA (SEA) to St. Louis, MO (STL) will usually cost between $265 to $441 per person if booking more than four weeks in advance. On average the very cheapest time to fly is late October with an average ticket price of $269. Due to high demand the most expensive time to fly is late July, with an average price of $531. Planning your trip to low-cost times can easily save you $262 on economy flights and even more on first-class flights. Generally, any price below $313 can be considered a good price for a round-trip SEA to STL flight.
See below for a graph of average weekly prices for the SEA to STL route. All prices are for round-trip tickets in USD.
Compared to other flights, the SEA to STL flight is much cheaper than the average and costs much less than the average flight leaving from Seattle. The average price per mile (for a direct flight) is $0.11, which is far below average.
Flight Prices by Day of the Week
Tuesday is usually the cheapest day to depart and return on this flight. Sundays are the most expensive days to fly out or take a return trip. Selecting flights on the least expensive days could save you up to $58 (16%) on this flight.
Departing prices are for round-trip flights returning on the day of departure. For example, a flight departing on Tuesday and returning a week later will cost an average of $300. Return trip prices are from the STL to SEA flight, and often highlight the quality of our data in showing the same trend.
Departing Prices by Day
Return Trip Prices by Day
Nonstop Flights and Layovers
Travelers looking to fly from SEA to STL can generally find a 0-layover flight. Because there is a direct flight option the real-world direct flight time of 4 hour 3 minutes may be realistic.
Flight Questions Answered
Still have questions about flying from SEA to STL? We’ve got answers.
Which airlines fly this route?
You can find 9 major airlines flying this route most often: Alaska, American, Cape Air, Delta, Frontier, Singapore Airlines, Southwest, Sun Country Airlines, United, and potentially more during busy seasons.
How far away is it from St Louis Lambert International Airport to Seattle/Tacoma International Airport?
The distance between the two airports is roughly 1705 miles or 2744 kilometers.
How long does it take to fly from SEA to STL?
The real-world flight time for a nonstop SEA to STL flight is about 4 hour 3 minutes.
How many flights go between Seattle, WA and St. Louis, MO?
It depends on the day of the week and the date, but a typical day might have around 101 available flights from SEA to STL.
Airport Location Info
|Origination airport name||Seattle/Tacoma International Airport|
|Country||the United States|
|Destination airport name||St Louis Lambert International Airport|
|City||St. Louis, MO|
|Country||the United States|
Late and Early Flight Data
Flights from SEA to STL tend to depart much later than the average flight. According to our recently updated data, 41% of flights departed 5 or more minutes late, and 19% of flights left 5 or more minutes early. On average you can expect to leave STL heading for SEA about 11 minutes late. This does significantly impact arrival time, as the average landing time in St. Louis, MO is about 10 minutes late. The numbers below show a recent average of take-off times versus the scheduled departure flight:
- Southwest: 19 minutes late
- Alaska: 8 minutes late
- Some airlines not reporting
Please note that while we’ve worked hard to analyzed tens of millions of flights to get you this data, we do not calculate current live prices or guarantee pricing. Please see our partners using the links above for current offers.