In terms of precipitation, rainfall in Porto Alegre ranges from 2.8 - 5.1 inches per month. September is typically the wettest month, when rainfall can reach 5.1 in. November is typically the driest time to visit Porto Alegre when rainfall is around 2.8 in.

If weather is an important factor for your trip to Porto Alegre, use this chart to help with planning. For those seeking warmer temperatures, February is the ideal time of year to visit, when temperatures reach an average of 77.0 F. Travelers looking to avoid the cold should look outside of June, when temperatures are typically at their lowest (around 55.4 F).

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

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

Most accurate provider : When it comes to deals on St. Louis-Porto Alegre flights, users find the pricing of FlightHub to be most consistent on Cheapflights vs. FlightHub Users can find the same prices on St. Louis-Porto Alegre flight deals on Cheapflights vs. FlightHub >95% of the time. Price accuracy is based on data collected from St. Louis-Porto Alegre flight searches over the past month and is updated monthly.

Most trusted provider : When it comes to deals on St. Louis-Porto Alegre flights, Cheapflights users trust FlightHub the most. FlightHub has received a user feedback score of 3 out of 3 stars (3 being the best), meaning they have been trusted the most by Cheapflights users looking for St. Louis-Porto Alegre flight deals. Provider user feedback score is based on Cheapflights searches over the past month and is updated monthly.

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

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

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

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

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

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

$1,148+ Flights from St. Louis to Porto Alegre

Home Search by date Vacation packages Hotels Flight deals Car rental Travel tips & news

Find cheap flights from St. Louis to Porto Alegre with Cheapflights

1. Tell us where you want to go

Enter your travel information like dates, passengers, trip type (one-way or round trip), and preferred cabin class then click “Find deals”

2. Select your favorite providers

We find the providers serving your travel needs. Choose up to four travel providers to compare side-by-side for flights, hotels, or car rentals.

3. Compare prices and book

Review each provider’s pricing and select the best option for you! Book through your favorite provider’s website for a seamless experience.

Cheap flight deals from St. Louis to Porto Alegre

Cheapest flights from St. Louis to Porto Alegre
Explore the most affordable flight options available from St. Louis to Porto Alegre. Find the lowest fares from popular airlines and budget airlines, with prices last updated on January 20, 2026.

Mon 8/175:18 pm

STL

POA

2 stops18h 47m

United Airlines

Thu 8/203:30 pm

POA

STL

2 stops32h 36m

United Airlines

Deal found 1/19

$1,148

Find flight deals from St. Louis to Porto Alegre

Most accurate provider	FlightHub 3 stars
Most trusted provider	FlightHub 1 star

Provider with most accurate pricing for Lambert-St Louis-Porto Alegre Salgado Filho flight deals.

Search Deals

Provider most trusted by Cheapflights users for Lambert-St Louis-Porto Alegre Salgado Filho flights.

Search Deals

Most accurate provider: When it comes to deals on St. Louis-Porto Alegre flights, users find the pricing of FlightHub to be most consistent on Cheapflights vs. FlightHub Users can find the same prices on St. Louis-Porto Alegre flight deals on Cheapflights vs. FlightHub >95% of the time. Price accuracy is based on data collected from St. Louis-Porto Alegre flight searches over the past month and is updated monthly.
Most trusted provider: When it comes to deals on St. Louis-Porto Alegre flights, Cheapflights users trust FlightHub the most. FlightHub has received a user feedback score of 3 out of 3 stars (3 being the best), meaning they have been trusted the most by Cheapflights users looking for St. Louis-Porto Alegre flight deals. Provider user feedback score is based on Cheapflights searches over the past month and is updated monthly.

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

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

See what other customers who have flown with LATAM Airlines from St. Louis to Porto Alegre have to say. You can also see how each airline compares in terms of entertainment options, comfort, food, crew/service, and boarding process.

LATAM Airlines

7.5

Good

1,909 reviews

Reviews

1 / 20

2.0

Mediocre

JC,Jan 2026

FLN - GRU

Plane was late in FLN and missed connection in GRU. No alternative was given to me until 6 hours later and I was delayed by over 12 hours total.

LATAM Airlines

7.5

Good

1,909 reviews

LATAM Airlines

7.5

Good

1,909 reviews

Reviews

1 / 20

2.0

Mediocre

JC,Jan 2026

FLN - GRU

Plane was late in FLN and missed connection in GRU. No alternative was given to me until 6 hours later and I was delayed by over 12 hours total.

Related info for your journey

Can I find deals for flights from St. Louis to Porto Alegre that include hotel bookings?
Yes. In addition to deals on St. Louis to Porto Alegre flights, Cheapflights offers vacation packages that include both flights and hotel.
How can I find direct flights from St. Louis to Porto Alegre?
After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from St. Louis to Porto Alegre.
Can I find deals for business class flights from St. Louis to Porto Alegre?
Yes. Cheapflights offers flight deals from St. Louis to Porto Alegre by cabin class. In addition to browsing deals, you can also filter by cabin class on the search results page after making a search.

Browse thousands of different options on Cheapflights for your next trip

Complete your trip

Porto Alegre car rentals

Porto Alegre Salgado Filho Airport car rentals

Other flights to Porto Alegre

Porto Alegre to Sao Paulo Guarulhos Intl Airport flights

Porto Alegre to Sao Paulo Congonhas Airport flights

Porto Alegre to Sao Paulo Guarulhos Intl Airport flights

Porto Alegre to Santiago flights

Top airline flying from St. Louis to Porto Alegre

Airline	Cheapest	Average	Flexibility	On-time
LATAM Airlines	Cheapest$1,167	Average$1,262	FlexibilityNo cancel fee	On-time81%

100% Free

Cheapflights is completely free to use, so you can start saving the moment you arrive.

Book with Flexibility

Our users can plan ahead with confidence and find flights with no change fees

Travel Smart

Millions of people come to us for their flight needs every year. We help make travel planning easy by providing useful insights and data-driven graphs that can inform your decisions.

This is the cheapest round-trip flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 8/17. Fares are subject to change and may not be available on all flights or dates of travel.

Find cheap flights from St. Louis to Porto Alegre with Cheapflights

1. Tell us where you want to go

2. Select your favorite providers

3. Compare prices and book

Cheap flight deals from St. Louis to Porto Alegre

Cheapest flights from St. Louis to Porto Alegre
Explore the most affordable flight options available from St. Louis to Porto Alegre. Find the lowest fares from popular airlines and budget airlines, with prices last updated on January 20, 2026.

Explore the most affordable flight options available from St. Louis to Porto Alegre. Find the lowest fares from popular airlines and budget airlines, with prices last updated on January 20, 2026.

Find flight deals from St. Louis to Porto Alegre

Most accurate provider

Most trusted provider

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

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

Reviews of airlines servicing Porto Alegre

See what other customers who have flown with LATAM Airlines from St. Louis to Porto Alegre have to say. You can also see how each airline compares in terms of entertainment options, comfort, food, crew/service, and boarding process.

Related info for your journey

Find useful and relevant information for your journey from St. Louis to Porto Alegre. 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 St. Louis to Porto Alegre that include hotel bookings?

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

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

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.

Complete your trip

Complete your trip to Porto Alegre by adding a car rental and/or hotel reservation to your travel itinerary.

Search flights from St. Louis to Porto Alegre by cabin class

Find flights from St. Louis to Porto Alegre, based on your preferred cabin class, be it economy, premium economy, business, or first class.

St. Louis and Porto Alegre flights

Browse other St. Louis and Porto Alegre flight options. Last updated on January 20, 2026.

Other flights from St. Louis

Browse through other flights departing from St. Louis. Flights are based on user searches made on Cheapflights and were last updated on January 20, 2026.

Popular flight searches

Check out other popular destinations found by fellow travelers in 2026

Other flights to Porto Alegre

Explore flights to Porto Alegre departing from other origins. Flights are based on user searches made on Cheapflights and were last updated on January 20, 2026.

Top airline flying from St. Louis to Porto Alegre

100% Free

Book with Flexibility

Travel Smart

$1,148+ Cheap flights from St. Louis (STL) to Porto Alegre (POA)

This is the cheapest round-trip flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 8/17. Fares are subject to change and may not be available on all flights or dates of travel.

Find cheap flights from St. Louis to Porto Alegre with Cheapflights

1. Tell us where you want to go

2. Select your favorite providers

3. Compare prices and book

Cheap flight deals from St. Louis to Porto Alegre

Cheapest flights from St. Louis to Porto AlegreExplore the most affordable flight options available from St. Louis to Porto Alegre. Find the lowest fares from popular airlines and budget airlines, with prices last updated on January 20, 2026.

Explore the most affordable flight options available from St. Louis to Porto Alegre. Find the lowest fares from popular airlines and budget airlines, with prices last updated on January 20, 2026.

Find flight deals from St. Louis to Porto Alegre

Most accurate provider

Most trusted provider

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

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

Reviews of airlines servicing Porto Alegre

See what other customers who have flown with LATAM Airlines from St. Louis to Porto Alegre have to say. You can also see how each airline compares in terms of entertainment options, comfort, food, crew/service, and boarding process.

Related info for your journey

Find useful and relevant information for your journey from St. Louis to Porto Alegre. 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 St. Louis to Porto Alegre that include hotel bookings?

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

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

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.

Complete your trip

Complete your trip to Porto Alegre by adding a car rental and/or hotel reservation to your travel itinerary.

Top airline flying from St. Louis to Porto Alegre

100% Free

Book with Flexibility

Travel Smart

Cheapest flights from St. Louis to Porto Alegre
Explore the most affordable flight options available from St. Louis to Porto Alegre. Find the lowest fares from popular airlines and budget airlines, with prices last updated on January 20, 2026.