What is the cheapest month to book a flight from Porto to St. Louis?

Currently, August is the cheapest month in which you can book a flight from Porto to St. Louis (average of $311). Flying from Porto 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.

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.

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).

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

When flying from Porto to St. Louis, the time of day you decide to fly out makes little to no difference towards the overall price you’ll pay on tickets.

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

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

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

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

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

Yes. Cheapflights offers flight deals from Porto 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.

$704+ Flights from Porto to St. Louis

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Cheap flight deals from Porto to St. Louis

Round-trip from	$1,223 (Air France)
One-way from	$704 (Thrive Travel)

From Porto to Lambert-St Louis

Search Deals

One-way flight from Porto to Lambert-St Louis

Search Deals

Find flight deals from Porto to St. Louis

Cheapest flights from Porto to St. Louis
Explore the most affordable flight options available from Porto to St. Louis. Find the lowest fares from popular airlines and budget airlines, with prices last updated on Juli 31, 2025.

Fr 8/159:20 amOPO - STL

2 stops20h 02mAir France

Di 8/195:11 pmSTL - OPO

2 stops16h 19mAir France

Deal found 7/30

$1,223

Fr 8/159:00 amOPO - STL

1 stop20h 35mLufthansa

Di 8/1911:27 amSTL - OPO

1 stop14h 18mLufthansa

Deal found 7/30

$1,373

Fr 8/157:10 amOPO - STL

2 stops18h 50mMultiple Airlines

Di 8/191:30 pmSTL - OPO

3 stops24h 55mMultiple Airlines

Deal found 7/30

$1,537

Best flights from Porto to St. Louis
Discover carefully curated flight deals from Porto to St. Louis that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated Juli 31, 2025.

Fr 8/159:20 amOPO - STL

2 stops20h 02mAir France

Di 8/195:11 pmSTL - OPO

2 stops16h 19mAir France

Deal found 7/30

$1,223

Fr 8/159:00 amOPO - STL

1 stop20h 35mLufthansa

Di 8/1911:27 amSTL - OPO

1 stop14h 18mLufthansa

Deal found 7/30

$1,373

Fr 8/157:10 amOPO - STL

2 stops18h 50mMultiple Airlines

Di 8/191:30 pmSTL - OPO

3 stops24h 55mMultiple Airlines

Deal found 7/30

$1,537

Last-minute flights from Porto to St. Louis
Discover last-minute flight deals from Porto to St. Louis. Data last updated Juli 31, 2025 and is based on user searches.

Fr 8/159:20 amOPO - STL

2 stops20h 02mAir France

Di 8/195:11 pmSTL - OPO

2 stops16h 19mAir France

Deal found 7/30

$1,223

Fr 8/159:00 amOPO - STL

1 stop20h 35mLufthansa

Di 8/1911:27 amSTL - OPO

1 stop14h 18mLufthansa

Deal found 7/30

$1,373

Fr 8/157:10 amOPO - STL

2 stops18h 50mMultiple Airlines

Di 8/191:30 pmSTL - OPO

3 stops24h 55mMultiple Airlines

Deal found 7/30

$1,537

One-way flights from Porto to St. Louis
Search for one-way flight options from Porto to St. Louis. Find affordable one-way fares based on user searches. Data last updated Juli 31, 2025.

Mi 10/296:00 amOPO - STL

1 stop13h 55mLufthansa

Deal found 7/29

$704

Fly from

Fly to

Route

Depart

Return

Price

PortoSt. Louis

OPO - STL

OPOSTL

Porto

Fr 8/15

9:20 am-11:22 pm

2 stops20h 02m

Lambert-St Louis

Di 8/19

5:11 pm-3:30 pm

2 stops16h 19m

$1,223

PortoSt. Louis

OPO - STL

OPOSTL

Porto

Fr 8/15

9:00 am-11:35 pm

1 stop20h 35m

Lambert-St Louis

Di 8/19

11:27 am-7:45 am

1 stop14h 18m

$1,373

PortoSt. Louis

OPO - STL

OPOSTL

Porto

Fr 8/15

7:10 am-8:00 pm

2 stops18h 50m

Lambert-St Louis

Di 8/19

1:30 pm-8:25 pm

3 stops24h 55m

$1,537

PortoSt. Louis

OPO - STL

OPOSTL

Porto

Mi 10/29

6:00 am-2:55 pm

1 stop13h 55m

$704

Flights are sorted by cheapest round-trip flights first.

Deals found on 7/29

Best time to book a flight from Porto to St. Louis

Have a flexible travel schedule? Discover the best time to fly to St. Louis from Porto 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.

Reviews of airlines servicing St. Louis

Read through reviews of airlines operating flights from Porto to St. Louis, such as Air France and Lufthansa. Reviews also offer insight into each airline's entertainment options, comfort, food, crew/service, and boarding process.

Air France

7.5

Good

1,465 reviews

Reviews

1 / 20

10.0

Excellent

SYLVIA,Apr 2025

TLV - CDG

A newer plane. The flight from TelAviv to Paris was on a new aircraft, wider seat. ,more privacy. Nice toilets. The flight from Paris to Santiago Chile was on a very old aircraft. Awful toilets, outmoded sits etc.

Air France

7.5

Good

1,465 reviews

Air France

7.5

Good

1,465 reviews

Reviews

1 / 20

10.0

Excellent

SYLVIA,Apr 2025

TLV - CDG

Lufthansa

6.8

Okay

7,269 reviews

Air France

7.5

Good

1,465 reviews

Reviews

1 / 20

10.0

Excellent

SYLVIA,Apr 2025

TLV - CDG

Related info for your journey

Can I find deals for flights from Porto to St. Louis that include hotel bookings?
Yes. In addition to deals on Porto to St. Louis flights, Cheapflights offers vacation packages that include both flights and hotel.
How can I find direct flights from Porto to St. Louis?
After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from Porto to St. Louis.
Can I find deals for business class flights from Porto to St. Louis?
Yes. Cheapflights offers flight deals from Porto 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 Porto to St. Louis?
Currently, August is the cheapest month in which you can book a flight from Porto to St. Louis (average of $311). Flying from Porto 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

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$704+ Cheap flights from Porto (OPO) to St. Louis (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 10/29. Fares are subject to change and may not be available on all flights or dates of travel.

Find cheap flights from Porto to St. Louis with Cheapflights

1. Tell us where you want to go

2. Select your favorite providers

3. Compare prices and book

Cheap flight deals from Porto to St. Louis

Round-trip from

One-way from

Find flight deals from Porto to St. Louis

Cheapest flights from Porto to St. LouisExplore the most affordable flight options available from Porto to St. Louis. Find the lowest fares from popular airlines and budget airlines, with prices last updated on Juli 31, 2025.

Explore the most affordable flight options available from Porto to St. Louis. Find the lowest fares from popular airlines and budget airlines, with prices last updated on Juli 31, 2025.

Cheapflights Fare Finder

Use the filters below to find and compare flights from Porto to St. Louis that are best for you.

Best time to book a flight from Porto to St. Louis

Have a flexible travel schedule? Discover the best time to fly to St. Louis from Porto with our price prediction graph.

Reviews of airlines servicing St. Louis

Read through reviews of airlines operating flights from Porto to St. Louis, such as Air France and Lufthansa. Reviews also offer insight into each airline's entertainment options, comfort, food, crew/service, and boarding process.

Related info for your journey

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

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

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

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

What is the cheapest month to book a flight from Porto to St. Louis?

Traveling to a place near St. Louis?

Browse thousands of different options on Cheapflights for your next trip

Toggle through the tabs below to find thousands of options on Cheapflights for your next trip.

Alternative routes for Porto to St. Louis

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Travel Smart

Cheapest flights from Porto to St. Louis
Explore the most affordable flight options available from Porto to St. Louis. Find the lowest fares from popular airlines and budget airlines, with prices last updated on Juli 31, 2025.