What are the cheapest airlines flying from St. Louis to Idaho Falls round-trip?

Hawaiian Airlines, at $298, was found to be the cheapest airline from St. Louis to Idaho Falls.Alternate airlines to your destination round-trip include Delta and Alaska Airlines. Hawaiian Airlines is priced at 44% lower than the current average price of a flight leaving 3 months from now.

What are the cheapest airlines to fly from St. Louis to Idaho Falls one-way?

To fly one-way, consider booking your trip with American Airlines, which is currently one of the cheapest options available, starting at $193. Delta flights start at $306 while deals on Alaska Airlines start at $338 one-way.

What is the cheapest day to fly from St. Louis to Idaho Falls?

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

In terms of precipitation, rainfall in Idaho Falls ranges from 0.6 - 2.0 inches per month. May is typically the wettest month, when rainfall can reach 2.0 in. July is typically the driest time to visit Idaho Falls when rainfall is around 0.6 in.

If weather is an important factor for your trip to Idaho Falls, 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 69.8 F. Travelers looking to avoid the cold should look outside of January, when temperatures are typically at their lowest (around 23.0 F).

What are the most popular airlines that fly from St. Louis to Idaho Falls?

Consider American Airlines, Delta or United Airlines when booking your flight. These represent the most popular airlines when flying from St. Louis to Idaho Falls.

What is the cheapest day to fly round-trip from St. Louis to Idaho Falls?

Users have found that leaving on a Monday can be a cost-effective option. It’s possible to save up to 30% on your flight compared to booking on days when demand is much higher.

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

Our data shows that January tends to be the cheapest month to fly to Idaho Falls from St. Louis. Users have commonly found prices around $539 for the month, but tickets can be as low as $307. Due to multiple factors, prepare for potentially higher prices in December.

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

A simple way to save on the total cost of your ticket is to fly from St. Louis to Idaho Falls at noon. If you’re flexible enough to do this you can expect to save up to 5% on your trip compared to booking a flight in the afternoon.

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

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

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

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

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

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

$193+ Flights from St. Louis to Idaho Falls

Q: How much does it cost to fly round-trip from St. Louis to Idaho Falls?

Airfare is below average for this route at the moment. St. Louis to Idaho Falls flights typically cost between $337 and $900 in September. The cheapest round-trip price found within the last 3 days was $298 on Hawaiian Airlines (Sep 27-Oct 1).

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Cheap flight deals from St. Louis to Idaho Falls

Round-trip from	$298 (Hawaiian Airlines)
One-way from	$193 (American Airlines)
Popular in	December
Cheapest in	January
Average price	$597

From Lambert-St Louis to Idaho Falls Fanning Field

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One-way flight from Lambert-St Louis to Idaho Falls Fanning Field

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Highest demand for flights based on searches. 4% potential increase in price ($22 potential increase over avg. RT price).

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Cheapest flight prices on average. 2% potential price decrease ($15 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 St. Louis to Idaho Falls

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

Sat 9/273:35 pmSTL - IDA

1 stop8h 04mHawaiian Airlines

Wed 10/16:13 amIDA - STL

1 stop7h 26mHawaiian Airlines

Deal found 7/28

$298

Wed 8/276:45 pmSTL - IDA

1 stop4h 42mDelta

Wed 9/36:00 amIDA - STL

1 stop6h 30mDelta

Deal found 7/27

$325

Sat 9/273:35 pmSTL - IDA

1 stop8h 04mAlaska Airlines

Wed 10/16:13 amIDA - STL

1 stop7h 26mAlaska Airlines

Deal found 7/27

$341

Thu 8/287:23 amSTL - IDA

1 stop6h 24mAmerican Airlines

Thu 9/41:35 pmIDA - STL

1 stop8h 15mAmerican Airlines

Deal found 7/27

$351

Wed 8/276:35 amSTL - IDA

2 stops11h 40mUnited Airlines

Wed 9/35:00 amIDA - STL

2 stops9h 44mUnited Airlines

Deal found 7/27

$529

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

Sat 9/273:35 pmSTL - IDA

1 stop8h 04mHawaiian Airlines

Wed 10/16:13 amIDA - STL

1 stop7h 26mHawaiian Airlines

Deal found 7/28

$298

Wed 8/276:45 pmSTL - IDA

1 stop4h 42mDelta

Wed 9/36:00 amIDA - STL

1 stop6h 30mDelta

Deal found 7/27

$325

Sat 9/273:35 pmSTL - IDA

1 stop8h 04mAlaska Airlines

Wed 10/16:13 amIDA - STL

1 stop7h 26mAlaska Airlines

Deal found 7/27

$341

Thu 8/287:23 amSTL - IDA

1 stop6h 24mAmerican Airlines

Thu 9/41:35 pmIDA - STL

1 stop8h 15mAmerican Airlines

Deal found 7/27

$351

Wed 8/276:35 amSTL - IDA

2 stops11h 40mUnited Airlines

Wed 9/35:00 amIDA - STL

2 stops9h 44mUnited Airlines

Deal found 7/27

$529

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

Fri 8/87:45 amSTL - IDA

1 stop7h 39mDelta

Fri 8/156:52 pmIDA - STL

1 stop4h 46mDelta

Deal found 7/28

$551

Wed 8/276:45 pmSTL - IDA

1 stop4h 42mDelta

Wed 9/36:00 amIDA - STL

1 stop6h 30mDelta

Deal found 7/27

$325

Wed 8/276:35 amSTL - IDA

2 stops11h 40mUnited Airlines

Wed 9/35:00 amIDA - STL

2 stops9h 44mUnited Airlines

Deal found 7/27

$529

Thu 8/287:23 amSTL - IDA

1 stop6h 24mAmerican Airlines

Thu 9/41:35 pmIDA - STL

1 stop8h 15mAmerican Airlines

Deal found 7/27

$351

One-way flights from St. Louis to Idaho Falls
Search for one-way flight options from St. Louis to Idaho Falls. Find affordable one-way fares based on user searches. Data last updated July 29, 2025.

Fri 8/296:00 amSTL - IDA

1 stop7h 47mAmerican Airlines

Deal found 7/28

$193

Fri 8/87:45 amSTL - IDA

1 stop7h 39mDelta

Deal found 7/28

$306

Fri 8/296:00 amSTL - IDA

1 stop17h 39mAlaska Airlines

Deal found 7/28

$338

Fri 8/296:15 amSTL - IDA

3 stops15h 39mUnited Airlines

Deal found 7/28

$1,075

Cheapflights Fare Finder

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

Fly from

Fly to

Route

Depart

Return

Price

St. LouisIdaho Falls

STL - IDA

STLIDA

Lambert-St Louis

Sat 9/27

3:35 pm-10:39 pm

1 stop8h 04m

Idaho Falls Fanning Field

Wed 10/1

6:13 am-2:39 pm

1 stop7h 26m

$298

St. LouisIdaho Falls

STL - IDA

STLIDA

Lambert-St Louis

Wed 8/27

6:45 pm-10:27 pm

1 stop4h 42m

Idaho Falls Fanning Field

Wed 9/3

6:00 am-1:30 pm

1 stop6h 30m

$325

St. LouisIdaho Falls

STL - IDA

STLIDA

Lambert-St Louis

Sat 9/27

3:35 pm-10:39 pm

1 stop8h 04m

Idaho Falls Fanning Field

Wed 10/1

6:13 am-2:39 pm

1 stop7h 26m

$341

St. LouisIdaho Falls

STL - IDA

STLIDA

Lambert-St Louis

Thu 8/28

7:23 am-12:47 pm

1 stop6h 24m

Idaho Falls Fanning Field

Thu 9/4

1:35 pm-10:50 pm

1 stop8h 15m

$351

St. LouisIdaho Falls

STL - IDA

STLIDA

Lambert-St Louis

Wed 8/27

6:35 am-5:15 pm

2 stops11h 40m

Idaho Falls Fanning Field

Wed 9/3

5:00 am-3:44 pm

2 stops9h 44m

$529

St. LouisIdaho Falls

STL - IDA

STLIDA

Lambert-St Louis

Fri 8/29

6:00 am-12:47 pm

1 stop7h 47m

$193

St. LouisIdaho Falls

STL - IDA

STLIDA

Lambert-St Louis

Fri 8/8

7:45 am-2:24 pm

1 stop7h 39m

$306

St. LouisIdaho Falls

STL - IDA

STLIDA

Lambert-St Louis

Fri 8/29

6:00 am-10:39 pm

1 stop17h 39m

$338

St. LouisIdaho Falls

STL - IDA

STLIDA

Lambert-St Louis

Fri 8/29

6:15 am-8:54 pm

3 stops15h 39m

$1,075

Flights are sorted by cheapest round-trip flights first.

Deals found on 7/28

Best time to book a flight from St. Louis to Idaho Falls

Have a flexible travel schedule? Discover the best time to fly to Idaho Falls 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.

Cheapflights Insights

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

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

Currently, October is the cheapest month in which you can book a flight from St. Louis to Idaho Falls (average of $380). Flying from St. Louis to Idaho Falls in December is currently the most expensive (average of $578). 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.

How much does it cost to fly round-trip from St. Louis to Idaho Falls?

Reviews of airlines servicing Idaho Falls

Peruse reviews from past customers who have flown with Alaska Airlines, Delta, and Hawaiian Airlines from St. Louis to Idaho Falls 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.

Alaska Airlines

8.0

Very good

10,000 reviews

Reviews

1 / 20

10.0

Excellent

Jonathan,Jul 2025

SEA - BOS

Fantastic Check-in with easy baggage drop. While it took a while to find out which was the gate, the boarding was a dream, the stewards were simply incredible and the flight fantastic.

Alaska Airlines

8.0

Very good

10,000 reviews

Alaska Airlines

8.0

Very good

10,000 reviews

Reviews

1 / 20

10.0

Excellent

Jonathan,Jul 2025

SEA - BOS

Fantastic Check-in with easy baggage drop. While it took a while to find out which was the gate, the boarding was a dream, the stewards were simply incredible and the flight fantastic.

Delta

8.0

Very good

7,977 reviews

Alaska Airlines

8.0

Very good

10,000 reviews

Reviews

1 / 20

10.0

Excellent

Jonathan,Jul 2025

SEA - BOS

Fantastic Check-in with easy baggage drop. While it took a while to find out which was the gate, the boarding was a dream, the stewards were simply incredible and the flight fantastic.

Hawaiian Airlines

7.8

Good

2,605 reviews

Alaska Airlines

8.0

Very good

10,000 reviews

Reviews

1 / 20

10.0

Excellent

Jonathan,Jul 2025

SEA - BOS

Fantastic Check-in with easy baggage drop. While it took a while to find out which was the gate, the boarding was a dream, the stewards were simply incredible and the flight fantastic.

United Airlines

7.4

Good

8,899 reviews

Alaska Airlines

8.0

Very good

10,000 reviews

Reviews

1 / 20

10.0

Excellent

Jonathan,Jul 2025

SEA - BOS

Fantastic Check-in with easy baggage drop. While it took a while to find out which was the gate, the boarding was a dream, the stewards were simply incredible and the flight fantastic.

American Airlines

7.2

Good

10,000 reviews

Alaska Airlines

8.0

Very good

10,000 reviews

Reviews

1 / 20

10.0

Excellent

Jonathan,Jul 2025

SEA - BOS

Fantastic Check-in with easy baggage drop. While it took a while to find out which was the gate, the boarding was a dream, the stewards were simply incredible and the flight fantastic.

Related info for your journey

What are the cheapest airlines flying from St. Louis to Idaho Falls round-trip?
Hawaiian Airlines, at $298, was found to be the cheapest airline from St. Louis to Idaho Falls.Alternate airlines to your destination round-trip include Delta and Alaska Airlines. Hawaiian Airlines is priced at 44% lower than the current average price of a flight leaving 3 months from now.
What are the cheapest airlines to fly from St. Louis to Idaho Falls one-way?
To fly one-way, consider booking your trip with American Airlines, which is currently one of the cheapest options available, starting at $193. Delta flights start at $306 while deals on Alaska Airlines start at $338 one-way.
Can I find deals for flights from St. Louis to Idaho Falls that include hotel bookings?
Yes. In addition to deals on St. Louis to Idaho Falls flights, Cheapflights offers vacation packages that include both flights and hotel.
How can I find direct flights from St. Louis to Idaho Falls?
After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from St. Louis to Idaho Falls.
Can I find deals for business class flights from St. Louis to Idaho Falls?
Yes. Cheapflights offers flight deals from St. Louis to Idaho Falls 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 St. Louis to Idaho Falls?
Currently, October is the cheapest month in which you can book a flight from St. Louis to Idaho Falls (average of $380). Flying from St. Louis to Idaho Falls in December is currently the most expensive (average of $578). 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 3 airlines flying from St. Louis to Idaho Falls

Airline	Cheapest	Average	Flexibility	On-time
Delta	Cheapest$273	Average$384	FlexibilityNo cancel fee	On-timeN/A
American Airlines	Cheapest$305	Average$796	FlexibilityNo cancel fee	On-time71%
United Airlines	Cheapest$400	Average$638	FlexibilityNo cancel fee	On-time69%

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$193+ Cheap flights from St. Louis to Idaho Falls (STL - IDA)

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 8/29. Fares are subject to change and may not be available on all flights or dates of travel.

Find cheap flights from St. Louis to Idaho Falls with Cheapflights

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2. Select your favorite providers

3. Compare prices and book

Cheap flight deals from St. Louis to Idaho Falls

Round-trip from

One-way from

Popular in

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Average price

Find flight deals from St. Louis to Idaho Falls

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

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

Cheapflights Fare Finder

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

Best time to book a flight from St. Louis to Idaho Falls

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

Cheapflights Insights

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

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

How much does it cost to fly round-trip from St. Louis to Idaho Falls?

Reviews of airlines servicing Idaho Falls

Peruse reviews from past customers who have flown with Alaska Airlines, Delta, and Hawaiian Airlines from St. Louis to Idaho Falls 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.

Related info for your journey

Find useful and relevant information for your journey from St. Louis to Idaho Falls. 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 St. Louis to Idaho Falls round-trip?

What are the cheapest airlines to fly from St. Louis to Idaho Falls one-way?

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

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

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

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

Traveling to a place near Idaho Falls?

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Alternative routes for St. Louis to Idaho Falls

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Top 3 airlines flying from St. Louis to Idaho Falls

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