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$141+ Cheap flights from Portland, ME to St. Louis (PWM - STL)

This is the cheapest one-way flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 7/19. Fares are subject to change and may not be available on all flights or dates of travel.
PWM — STL
Jun 17 — Jun 241
Tue 6/17
Tue 6/24
1 adult, Economy
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Cheap flight deals from Portland to St. Louis

Discover tips and strategies to find the most affordable flight options for your journey from Portland (PWM) to St. Louis (STL). Learn about various techniques such as flexible date searches, comparing prices across and setting up price alerts. Use these methods to find the cheapest flights available for your travel needs. Data last updated June 12, 2025.

Round-trip from

$317
(Delta)

One-way from

$141
(FlightHub)

Popular in

December

Cheapest in

February

Average price

$396
From Portland to Lambert-St Louis
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One-way flight from Portland to Lambert-St Louis
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Highest demand for flights based on searches. 9% potential increase in price ($43 potential increase over avg. RT price).
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Cheapest flight prices on average. 3% potential price decrease ($13 potential savings vs. average RT price).
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Average for round-trip flights in June 2025
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Find flight deals from Portland to St. Louis

Cheapest flights from Portland to St. Louis
Explore the most affordable flight options available from Portland to St. Louis. Find the lowest fares from popular airlines and budget airlines, with prices last updated on June 12, 2025.

This Delta deal was found by Cheapflights users on 6/11. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 7/26:03 amPWM - STL
1 stop6h 28mDelta
Sat 7/51:30 pmSTL - PWM
1 stop7h 07mDelta
Deal found 6/11$317
This Southwest deal was found by Cheapflights users on 6/11. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 8/85:50 amPWM - STL
1 stop6h 40mSouthwest
Sat 8/2312:30 pmSTL - PWM
1 stop8h 30mSouthwest
Deal found 6/11$357
This American Airlines deal was found by Cheapflights users on 6/10. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 7/246:15 amPWM - STL
1 stop7h 28mAmerican Airlines
Mon 7/284:28 pmSTL - PWM
1 stop5h 17mAmerican Airlines
Deal found 6/10$387
This Mytrip deal was found by Cheapflights users on 6/10. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 6/258:07 pmPWM - STL
2 stops21h 57mMultiple Airlines
Sun 6/296:12 amSTL - PWM
1 stop28h 11mMultiple Airlines
Deal found 6/10$432
This United Airlines deal was found by Cheapflights users on 6/11. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 7/103:50 pmPWM - STL
1 stop8h 45mUnited Airlines
Wed 7/168:00 amSTL - PWM
1 stop5h 24mUnited Airlines
Deal found 6/11$460

Cheapflights Fare Finder

Customize your flight search to find flights from Portland to St. Louis that fit within your specific budget. Explore options based on user searches and filter the results based on your desired price range. Find flights that match your budget for a cost-effective journey. Over the last 7 days, Cheapflights users made 2,558,603 searches. Data last updated June 12, 2025.
Use the filters below to find and compare flights from Portland to St. Louis that are best for you.

Fly from

Portland

Fly to

St. Louis

Route

Depart

Return

Price

PortlandSt. Louis

PWM - STL

PWMSTL

Portland

Wed 7/2

6:03 am-11:31 am

1 stop6h 28m

Lambert-St Louis

Sat 7/5

1:30 pm-9:37 pm

1 stop7h 07m

$317

PortlandSt. Louis

PWM - STL

PWMSTL

Portland

Fri 8/8

5:50 am-11:30 am

1 stop6h 40m

Lambert-St Louis

Sat 8/23

12:30 pm-10:00 pm

1 stop8h 30m

$357

PortlandSt. Louis

PWM - STL

PWMSTL

Portland

Thu 7/24

6:15 am-12:43 pm

1 stop7h 28m

Lambert-St Louis

Mon 7/28

4:28 pm-10:45 pm

1 stop5h 17m

$387

PortlandSt. Louis

PWM - STL

PWMSTL

Portland

Wed 6/25

8:07 pm-5:04 pm

2 stops21h 57m

Lambert-St Louis

Sun 6/29

6:12 am-11:23 am

1 stop28h 11m

$432

PortlandSt. Louis

PWM - STL

PWMSTL

Portland

Thu 7/10

3:50 pm-11:35 pm

1 stop8h 45m

Lambert-St Louis

Wed 7/16

8:00 am-2:24 pm

1 stop5h 24m

$460

PortlandSt. Louis

PWM - STL

PWMSTL

Portland

Sat 7/19

6:58 pm-11:47 pm

1 stop29h 49m

$141

PortlandSt. Louis

PWM - STL

PWMSTL

Portland

Tue 8/12

6:00 am-12:35 pm

1 stop7h 35m

$143

PortlandSt. Louis

PWM - STL

PWMSTL

Portland

Tue 8/12

6:00 am-4:06 pm

2 stops11h 06m

$148

PortlandSt. Louis

PWM - STL

PWMSTL

Portland

Sun 7/13

12:46 pm-7:31 pm

1 stop7h 45m

$155

PortlandSt. Louis

PWM - STL

PWMSTL

Portland

Mon 8/4

5:40 pm-11:20 pm

1 stop6h 40m

$180

Flights are sorted by cheapest round-trip flights first.

Deals found on 6/9

Showing 1-10 of 12 results
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Best time to book a flight from Portland to St. Louis

Have a flexible travel schedule? Discover the best time to fly to St. Louis from Portland with our price prediction graph.
Estimated round-trip price
Rates are based on past data. Find the cheapest month and day to book your flight based on your travel requirements, then search for cheap deals.

Cheapflights Insights

Everything you need to know about your flight from Portland to St. Louis

What is the cheapest month to book a flight from Portland, Maine to St. Louis?

Currently, August is the cheapest month in which you can book a flight from Portland, Maine to St. Louis (average of $311). Flying from Portland, Maine to St. Louis in March is currently the most expensive (average of $356). 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.

What is the cheapest time of day to fly from PWM to STL?

Find hourly flight availability from Portland to St. Louis. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated June 12, 2025.

When flying from Portland, Maine to St. Louis, the time of day you fly usually plays a role in the price. Save by searching for a flight in the afternoon, which can drop the price by up to 28% versus a flight at noon.

Rainfall in St. Louis by month

Plan your trip to St. Louis by taking into account the average rainfall totals by month.

In terms of precipitation, rainfall in St. Louis ranges from 2.2 - 4.7 inches per month. May is typically the wettest month, when rainfall can reach 4.7 in. February is typically the driest time to visit St. Louis when rainfall is around 2.2 in.

Temperature in St. Louis by month

Plan your trip to St. Louis by taking into account the average temperature totals by month.

If weather is an important factor for your trip to St. Louis, use this chart to help with planning. For those seeking warmer temperatures, July is the ideal time of year to visit, when temperatures reach an average of 80.6 F. Travelers looking to avoid the cold should look outside of January, when temperatures are typically at their lowest (around 32.0 F).

Reviews of airlines servicing St. Louis

Get insights into the airlines that provide service to St. Louis. Read reviews, discover amenities, and learn about the overall travel experience offered by airlines. Use this information to make informed decisions when choosing an airline for your flight to St. Louis. Reviews last updated June 12, 2025.
Peruse reviews from past customers who have flown with Southwest, Delta and United Airlines from Portland to St. Louis to help guide your decision. You can also see how each airline stacks up in terms of entertainment options, comfort, food, crew/service, and boarding process.
Southwest
8.0
Very good
4,287 reviews

Boarding

8.2

Comfort

8.0

Entertainment

7.6

Overall

8.0

Food

7.1

Crew

8.6

Reviews

1 / 20
8.0
Excellent

John,May 2025

PVD - BNA

It’s southwest so no frills but clean, efficient and got me to my location.
Southwest
8.0
Very good
4,287 reviews
Southwest
8.0
Very good
4,287 reviews

Boarding

8.2

Comfort

8.0

Entertainment

7.6

Overall

8.0

Food

7.1

Crew

8.6

Reviews

1 / 20
8.0
Excellent

John,May 2025

PVD - BNA

It’s southwest so no frills but clean, efficient and got me to my location.
Delta
8.0
Very good
7,946 reviews
Southwest
8.0
Very good
4,287 reviews

Boarding

8.2

Comfort

8.0

Entertainment

7.6

Overall

8.0

Food

7.1

Crew

8.6

Reviews

1 / 20
8.0
Excellent

John,May 2025

PVD - BNA

It’s southwest so no frills but clean, efficient and got me to my location.
United Airlines
7.4
Good
8,790 reviews
Southwest
8.0
Very good
4,287 reviews

Boarding

8.2

Comfort

8.0

Entertainment

7.6

Overall

8.0

Food

7.1

Crew

8.6

Reviews

1 / 20
8.0
Excellent

John,May 2025

PVD - BNA

It’s southwest so no frills but clean, efficient and got me to my location.
American Airlines
7.2
Good
10,000 reviews
Southwest
8.0
Very good
4,287 reviews

Boarding

8.2

Comfort

8.0

Entertainment

7.6

Overall

8.0

Food

7.1

Crew

8.6

Reviews

1 / 20
8.0
Excellent

John,May 2025

PVD - BNA

It’s southwest so no frills but clean, efficient and got me to my location.
Sun Country Air
6.9
Okay
345 reviews
Southwest
8.0
Very good
4,287 reviews

Boarding

8.2

Comfort

8.0

Entertainment

7.6

Overall

8.0

Food

7.1

Crew

8.6

Reviews

1 / 20
8.0
Excellent

John,May 2025

PVD - BNA

It’s southwest so no frills but clean, efficient and got me to my location.

Related info for your journey

Find useful and relevant information for your journey from Portland to St. Louis. Access travel guides, tips, and recommendations to enhance your travel experience. Get information about local attractions, weather, transportation options, and more.

  • What are the cheapest airlines flying from Portland, Maine to St. Louis round-trip?

    Flying on Delta is currently your cheapest option to St. Louis, with prices starting at $317. Additional round-trip tickets that might be worth considering are offered by Southwest and American Airlines, with the lowest prices starting at $357 and $387, respectively. Delta is 22% cheaper than the average price of flights available within the next 90 days to this destination.

  • What are the cheapest airlines to fly from Portland, Maine to St. Louis one-way?

    For one-way options, check prices for Frontier. According to our data, you can fly for as low as $141. Users have also found prices from $143 and $148 on American Airlines and Delta, respectively.

  • Can I find deals for flights from Portland to St. Louis that include hotel bookings?

    Yes. In addition to deals on Portland to St. Louis flights, Cheapflights offers vacation packages that include both flights and hotel.

  • How can I find direct flights from Portland to St. Louis?

    After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from Portland to St. Louis.

  • Can I find deals for business class flights from Portland to St. Louis?

    Yes. Cheapflights offers flight deals from Portland to St. Louis by cabin class. In addition to browsing deals, you can also filter by cabin class on the search results page after making a search.

  • What is the cheapest month to book a flight from Portland, Maine to St. Louis?

    Currently, August is the cheapest month in which you can book a flight from Portland, Maine to St. Louis (average of $311). Flying from Portland, Maine to St. Louis in March is currently the most expensive (average of $356). 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.

See more FAQs

Traveling to a place near Portland?

Book flights to Portland if you plan to visit one of these locations
O'Fallon
Maryland Heights
Fairview Heights
Collinsville
Eureka
St. Peters
Glencoe
Festus
Alton
Farmington

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Top 4 airlines flying from Portland to St. Louis

Discover the top 4 airlines that operate flights from Portland to St. Louis. Compare their services, reliability, and customer satisfaction ratings to choose the airline that best suits your travel preferences and needs. Over the last 7 days, Cheapflights users made 2,558,603 searches. Data last updated June 12, 2025.
AirlineCheapestAverageFlexibilityOn-time
American AirlinesCheapest$308Average$420FlexibilityNo cancel feeOn-time71%
DeltaCheapest$333Average$428FlexibilityNo cancel feeOn-timeN/A
United AirlinesCheapest$341Average$456FlexibilityNo cancel feeOn-time69%
SouthwestCheapest$351Average$456FlexibilityNo cancel feeOn-time63%

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