What is the cheapest airline to fly from Casper to St. Louis round-trip?

United Airlines, at $338, was found to be the cheapest airline from Casper to St. Louis.. You may be able to fly from Casper to St. Louis for 32% less than the average price by searching for this airline.

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

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

Travelers seeking maximum savings on their Casper to St. Louis flight should consider departing on Saturday mornings when fares are most often at their lowest. Saturday afternoons flights should be avoided if possible as fares are typically the most expensive at this time.

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 day to fly round-trip from Casper to St. Louis?

Leaving on a Wednesday is a viable option for saving on travel. Heavily demanded days of the week can typically drive up the prices you see. Booking your travel for a less competitive day can save up to 76% on the overall cost on flights from Casper to St. Louis.

What is the cheapest month to fly from Casper to St. Louis?

Due to multiple factors, expect to potentially pay more when booking in July. For low rates, August can be a great choice for travel to St. Louis. Flights to St. Louis from Casper in August are about $500 on average during August, but can be found for as low as $338.

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

Unlike in the afternoon, when flights are generally more expensive, you can save up to 32% on flights from Casper to St. Louis by exploring options for tickets at noon.

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

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

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

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

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

Yes. Cheapflights offers flight deals from Casper 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.

$338+ Flights from Casper to St. Louis

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Cheap flight deals from Casper to St. Louis

Round-trip from	$338 (United Airlines)
Popular in	July
Cheapest in	August
Average price	$674

From Casper Natrona County to Lambert-St Louis

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High demand for flights, 3% potential price rise

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Cheapest flight prices on average. 3% potential price decrease ($20 potential savings vs. average RT price).

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Average for round-trip flights in July 2025

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Find flight deals from Casper to St. Louis

Cheapest flights from Casper to St. Louis
Explore the most affordable flight options available from Casper to St. Louis. Find the lowest fares from popular airlines and budget airlines, with prices last updated on julio 29, 2025.

mié. 8/275:50 pmCPR - STL

1 stop5h 03mUnited Airlines

mié. 9/35:15 amSTL - CPR

1 stop6h 35mUnited Airlines

Deal found 7/28

$338

Best flights from Casper to St. Louis
Discover carefully curated flight deals from Casper to St. Louis that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated julio 29, 2025.

mié. 8/275:50 pmCPR - STL

1 stop5h 03mUnited Airlines

mié. 9/35:15 amSTL - CPR

1 stop6h 35mUnited Airlines

Deal found 7/28

$338

Last-minute flights from Casper to St. Louis
Discover last-minute flight deals from Casper to St. Louis. Data last updated julio 29, 2025 and is based on user searches.

dom. 8/35:59 pmCPR - STL

1 stop5h 00mUnited Airlines

mar. 8/55:15 amSTL - CPR

1 stop6h 39mUnited Airlines

Deal found 7/29

$823

mié. 8/275:50 pmCPR - STL

1 stop5h 03mUnited Airlines

mié. 9/35:15 amSTL - CPR

1 stop6h 35mUnited Airlines

Deal found 7/28

$338

Fly from

Fly to

Route

Depart

Return

Price

CasperSt. Louis

CPR - STL

CPRSTL

Casper Natrona County

mié. 8/27

5:50 pm-11:53 pm

1 stop5h 03m

Lambert-St Louis

mié. 9/3

5:15 am-10:50 am

1 stop6h 35m

$338

Flights are sorted by cheapest round-trip flights first.

Deals found on 7/28

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

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

Get a feel of what it's like to fly with United Airlines from Casper to St. Louis by reading reviews from past customers. Users have also rated airlines in terms of entertainment options, comfort, food, crew/service, and boarding process.

United Airlines

7.4

Good

8,899 reviews

Reviews

1 / 20

2.0

Mediocre

Deb,Jan 2025

MKE - ORD

It was terrible! So much to say, but in a nutshell we used vouchers from United because our last trip with them was awful with many mishaps and errors made. Unfortunately, this trip was even worse!

United Airlines

7.4

Good

8,899 reviews

United Airlines

7.4

Good

8,899 reviews

Reviews

1 / 20

2.0

Mediocre

Deb,Jan 2025

MKE - ORD

It was terrible! So much to say, but in a nutshell we used vouchers from United because our last trip with them was awful with many mishaps and errors made. Unfortunately, this trip was even worse!

Related info for your journey

What is the cheapest airline to fly from Casper to St. Louis round-trip?
United Airlines, at $338, was found to be the cheapest airline from Casper to St. Louis.. You may be able to fly from Casper to St. Louis for 32% less than the average price by searching for this airline.
Can I find deals for flights from Casper to St. Louis that include hotel bookings?
Yes. In addition to deals on Casper to St. Louis flights, Cheapflights offers vacation packages that include both flights and hotel.
How can I find direct flights from Casper to St. Louis?
After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from Casper to St. Louis.
Can I find deals for business class flights from Casper to St. Louis?
Yes. Cheapflights offers flight deals from Casper 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 Casper to St. Louis?
Currently, August is the cheapest month in which you can book a flight from Casper to St. Louis (average of $311). Flying from Casper 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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Top airline flying from Casper to St. Louis

Airline	Cheapest	Average	Flexibility	On-time
United Airlines	Cheapest$301	Average$511	FlexibilityNo cancel fee	On-time69%

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$338+ Cheap flights from Casper to St. Louis (CPR - STL)

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 8/27. Fares are subject to change and may not be available on all flights or dates of travel.

Find cheap flights from Casper 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 Casper to St. Louis

Round-trip from

Popular in

Cheapest in

Average price

Find flight deals from Casper to St. Louis

Cheapest flights from Casper to St. LouisExplore the most affordable flight options available from Casper to St. Louis. Find the lowest fares from popular airlines and budget airlines, with prices last updated on julio 29, 2025.

Explore the most affordable flight options available from Casper to St. Louis. Find the lowest fares from popular airlines and budget airlines, with prices last updated on julio 29, 2025.

Cheapflights Fare Finder

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

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

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

Reviews of airlines servicing St. Louis

Get a feel of what it's like to fly with United Airlines from Casper to St. Louis by reading reviews from past customers. Users have also rated airlines 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 Casper 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 is the cheapest airline to fly from Casper to St. Louis round-trip?

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

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

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

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

Traveling to a place near St. Louis?

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Alternative routes for Casper to St. Louis

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Top airline flying from Casper to St. Louis

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Travel Smart

Cheapest flights from Casper to St. Louis
Explore the most affordable flight options available from Casper to St. Louis. Find the lowest fares from popular airlines and budget airlines, with prices last updated on julio 29, 2025.