Cheap flights from Washington to St. Louis from $88

In general, January is the cheapest month to fly from State of Washington to St. Louis. Due to it being the ‘off-season’ during this time, you can expect flight prices to be around $88. The month of September is another great option to travel to St. Louis, with average flight prices from State of Washington averaging around $94.

The cheapest day to depart on your flight to St. Louis is on a Tuesday when prices can be found for as low as $372. This is often the case because there is less demand to fly during this day of the week. If your travel schedule is flexible, try to avoid departing on a Monday because tickets tend to average around $547. These prices are subject to change though, so be sure to set up a Price Alert for flights to St. Louis.

Flying to St. Louis from State of Washington at noon is the least expensive time of day to depart. momondo users have found prices as low as $277 when looking at flights departing at noon. In the afternoon is when there is more demand to fly to St. Louis, so prices are often more expensive at around $445 per ticket.

Fly from Seattle/Tacoma Intl to Lambert-St Louis for the best Washington - Lambert-St Louis flight prices

You are more likely to see cheaper flights to St. Louis from State of Washington when booking weeks ahead of your departure date. In general, you can expect to find flights to St. Louis for around $383 when searching weeks out. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to St. Louis from State of Washington for as low as $249 on momondo.

Frontier, United Airlines, and Alaska Airlines are the most popular carriers operating from Washington to Lambert-St Louis

Alaska Airlines, Delta and Southwest are the top three most popular airlines that fly to St. Louis from State of Washington according to our data. Alaska Airlines is the first choice among our users, with 69% of people opting to fly with this airline when traveling to St. Louis. Keep in mind that there are 7 different airlines that fly to St. Louis on a routine basis, so you have a few additional options to choose from.

The number of flights available between State of Washington and St. Louis is 2 per day as of May 2026. The most frequent departure time is 5:00PM, with 72% of daily flights leaving in the afternoon.

The number of flights available between State of Washington and St. Louis is 16 per week as of May 2026. The most frequent departure day is Mon, with 38% of weekly flights leaving on this day.