Cheap flights from Idaho to St. Louis from $144
This is the cheapest one-way flight price found by a momondo user in the last 72 hours by searching for a flight from Idaho to St. Louis departing on 7/1. Fares may change, and may not be available for all flights or travel dates. Click the price to refresh the search for this deal.
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How to get the cheapest flight ticket from Idaho to St. Louis
Look no further. We've gone through all the searches for this route on momondo so you have the important information and insights to find the cheapest flight ticket for your trip
What is the cheapest month to fly to St. Louis?
In general, April is the cheapest month to fly from Idaho to St. Louis. Due to it being the ‘off-season’ during this time, you can expect flight prices to be around $334. The month of August is another great option to travel to St. Louis, with average flight prices from Idaho averaging around $341.
What is the cheapest day to depart on your flight to St. Louis?
The cheapest day to depart on your flight to St. Louis is on a Tuesday when prices can be found for as low as $391. This is often the case because there is less demand to fly during this day of the week. If your travel schedule is flexible, try to avoid departing on a Monday because tickets tend to average around $561. These prices are subject to change though, so be sure to set up a Price Alert for flights to St. Louis.
What is the cheapest time of day to depart on your flight to St. Louis?
Flying to St. Louis from Idaho in the afternoon is the least expensive time of day to depart. momondo users have found prices as low as $410 when looking at flights departing in the afternoon. In the morning is when there is more demand to fly to St. Louis, so prices are often more expensive at around $496 per ticket.
How far in advance should I book a flight to St. Louis?
You are more likely to see cheaper flights to St. Louis from Idaho when booking weeks ahead of your departure date. In general, you can expect to find flights to St. Louis for around $436 when searching weeks out. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to St. Louis from Idaho for as low as $334 on momondo.
What is the cheapest airline that flies from Idaho to Lambert-St Louis?
American Airlines, Southwest, and Hawaiian Airlines are the most popular carriers operating from Idaho to Lambert-St Louis
What airlines fly to St. Louis?
Delta, United Airlines and Southwest are the top three most popular airlines that fly to St. Louis from Idaho according to our data. Delta is the first choice among our users, with 43% of people opting to fly with this airline when traveling to St. Louis. Keep in mind that there are 5 different airlines that fly to St. Louis on a routine basis, so you have a few additional options to choose from.
How many flights depart from Idaho to St. Louis on average per week?
The number of flights available between Idaho and St. Louis is 2 per week as of June 2025. The most frequent departure day is Tue, with 50% of weekly flights leaving on this day.
How long does it take to fly to St. Louis?
Flight times from Idaho to St. Louis vary, but if you’re flying out of Hailey and flying into St. Louis (one of the most popular routes), then the duration is 4h 38m on average. Another popular route from Idaho to St. Louis is flying from Idaho Falls to St. Louis, which will take roughly 4h 44m. Keep in mind that layovers or delays could extend your travel time.
Cheap Idaho to St. Louis flight deals and tips
Find info about flight duration, direct flights, and airports for your flight from Idaho to St. Louis
When did momondo last update prices for flights from Idaho to Lambert-St Louis Airport?
Prices for flights from Idaho to Lambert-St Louis Airport are refreshed on a daily basis.
How many operators does momondo search for flights from Idaho to Lambert-St Louis Airport?
As of June 2025, there are 5 operators available to choose from for flights from Idaho to Lambert-St Louis Airport.
How old do you have to be to fly from Idaho to Lambert-St Louis Airport?
The minimum age a child must be to fly alone is five but airlines that offer an unaccompanied minor (UNMR) service will have their own age restrictions, including rules around flight length, timings, and stopovers. We always recommend checking with the individual airline you are booking with to travel from Idaho to Lambert-St Louis Airport.
What documentation or ID do you need to fly to Lambert-St Louis Airport?
The required travel and health documents for your Lambert-St Louis Airport trip may vary depending on your itinerary and personal circumstances. As a general rule, you should carry multiple documents, including a national ID card or driver's license and a passport valid for six months after your intended arrival at Lambert-St Louis Airport. We recommend that you seek guidance from your airline or a reliable third party such as IATA.
Best airlines flying from Idaho to St. Louis
Compare and see reviews for airlines that fly from Idaho to St. Louis with momondo
| Airline | Rating | Free Cancellation | Price | ||
|---|---|---|---|---|---|
| PriceFrom $208 | Free Cancellation | Rating 8.0 7,964 reviews | |||
| PriceFrom $226 | Free Cancellation | Rating 7.2 10,000 reviews | |||
| PriceFrom $292 | Free Cancellation | Rating 7.4 8,810 reviews | |||
| PriceFrom $306 | Free Cancellation | Rating 8.0 4,280 reviews | |||
| PriceFrom $326 | Free Cancellation | Rating 8.0 10,000 reviews |
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Why should I use momondo to find a flight deal from Idaho to St. Louis?
We help find the flight that best suits your needs, momondo compares prices from hundreds of airlines and travel agents and helps you filter them to find the best flight from Idaho to St. Louis for you.
Can I find flights from Idaho to St. Louis with flexible booking policies on momondo?
Yes. momondo enables you to select and highlight flights to St. Louis from Idaho with this policy.
How can momondo help me find flights from Idaho to St. Louis?
Once you have performed a search for Idaho to St. Louis flights, momondo helps you find the right one by offering useful filters to narrow down your flight selection. Flights can be filtered by multiple factors such as airline, airport and price; but also by other criteria like aircraft type and payment method.
I’m not ready to book a flight from Idaho to St. Louis right now. Can momondo alert me if prices change?
If you are simply researching potential flights to St. Louis, momondo offers a useful price alert feature which will track prices for flights to St. Louis from Idaho and alert you when they change.