The cheapest times to fly from MDT to STL are

  • August 13th to November 18th (except the week of September 24th)
  • December 3rd to February 25th (except the week of December 17th)

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 MDT to STL is late October. Prices can be as high as $883 for Monday flights during early to mid May, or as low as $285 for Wednesday flights around late October.


When to Fly to St. Louis

Flying from Harrisburg, PA (MDT) to St. Louis, MO (STL) will usually cost between $286 to $448 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 $309. Due to high demand the most expensive time to fly is early to mid May, with an average price of $554. Planning your trip to low-cost times can easily save you $244 on economy flights and even more on first-class flights. Generally, any price below $326 can be considered a good price for a round-trip MDT to STL flight.

See below for a graph of average weekly prices for the MDT to STL route. All prices are for round-trip tickets in USD.

MDT to STL Flight Prices

Compared to other flights, the MDT to STL flight is much cheaper than the average and costs much less than the average flight leaving from Harrisburg. The average price per mile (for a direct flight) is $0.28, which is below average.


Flight Prices by Day of the Week

Wednesday is usually the cheapest day to depart and return on this flight. Mondays are the most expensive days to fly to St. Louis, and Fridays are the most expensive days to return to Harrisburg. Selecting flights on the least expensive days could save you up to $72 (19%) on this flight.

Departing prices are for round-trip flights returning on the day of departure. For example, a flight departing on Wednesday and returning a week later will cost an average of $301. Return trip prices are from the STL to MDT flight, and often highlight the quality of our data in showing the same trend.

Departing Prices by Day

Departure Day Prices

Return Trip Prices by Day

Return Day Prices


Nonstop Flights and Layovers

Travelers looking to fly from MDT to STL can generally find a 1-layover flight. Because there is not usually a direct flight option the real-world direct flight time of 2 hour 18 minutes may not be realistic.


Flight Questions Answered

Still have questions about flying from MDT to STL? We’ve got answers.

Which airlines fly this route?

You can find 5 major airlines flying this route most often: American, Cape Air, Delta, Frontier, United, and potentially more during busy seasons.

How far away is it from St Louis Lambert International Airport to Harrisburg International Airport?

The distance between the two airports is roughly 732 miles or 1178 kilometers.

How long does it take to fly from MDT to STL?

The real-world flight time for a nonstop MDT to STL flight is about 2 hour 18 minutes.

How many flights go between Harrisburg, PA and St. Louis, MO?

It depends on the day of the week and the date, but a typical day might have around 69 available flights from MDT to STL.


Airport Location Info


Departing Airport

Origination codeMDT
Origination airport nameHarrisburg International Airport
CityHarrisburg, PA
Countrythe United States

Return Airport

Destination codeSTL
Destination airport nameSt Louis Lambert International Airport
CitySt. Louis, MO
Countrythe United States


Other Resources

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.