Cheap Flights from St. Louis (STL) to Boulder (WBU)

Popular airlines from St. Louis Lambert Intl. Airport (STL) to Boulder, CO (WBU-Boulder Municipal)

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Frequently asked questions

How much does a flight from Lambert-St. Louis Intl. Airport (STL) to Boulder, CO (WBU-Boulder Municipal) cost?
Snag a cheap one-way flight or cheap return flight from Lambert-St. Louis Intl. Airport (STL) to Boulder, CO (WBU-Boulder Municipal) with Expedia. Enter your travel dates and sort by "Price (lowest to highest)" to see our cheapest flight deals on this route.
What is the cheapest month to fly from Lambert-St. Louis Intl. Airport (STL) to Boulder, CO (WBU-Boulder Municipal)?
The cheapest month to fly from STL to WBU is , when demand is low. Off-peak months are generally when airlines offer lower prices between these airports.
What is the cheapest airline that flies from Lambert-St. Louis Intl. Airport (STL) to Boulder, CO (WBU-Boulder Municipal)?
To find the cheapest airline that'll fly you from STL to WBU, use Expedia's filter tool. Customize your search based on your travel style, such as preferred carriers and ideal departure window. You can then sort your results by "Price (lowest to highest)" to see the cheapest fares upfront.
How many flights per day from Lambert-St. Louis Intl. Airport (STL) to Boulder, CO (WBU-Boulder Municipal)?
There aren't any daily nonstop flights departing from Lambert-St. Louis Intl. Airport (STL) to Boulder, CO (WBU-Boulder Municipal). But you can opt for flights with layovers. Filter your search on Expedia to include one or more stops, and you'll be soaring above the clouds in no time.
What day of the week has the most flights from STL to WBU?
Typically you'll find the largest variety of flight choices on a Friday. Tuesdays tend to be the quietest.* However, this can vary based on the time of year, carrier and other factors.*Busiest/quietest day to travel is based on Expedia flight demand through January to December 2024.
What is the best time to fly from Lambert-St. Louis Intl. Airport (STL) to Boulder, CO (WBU-Boulder Municipal)?
To avoid potential delays on the Lambert-St. Louis Intl. Airport (STL) to Boulder, CO (WBU-Boulder Municipal) route, travel before 3 PM. Departures after this time have a 22% higher chance of cancellation.**Most reliable time of the day and month to travel recommendation is based on January through August 2024 flight status data sourced from OAG's global flight data platform.
What airports do you fly into for Boulder from Lambert-St. Louis Intl. Airport (STL)?
Denver Intl. Airport (DEN) is the only airport in Boulder with direct flights from Lambert-St. Louis Intl. Airport (STL). Explore your options and discover affordable fares on Expedia.
Is it cheaper to buy a plane ticket from Lambert-St. Louis Intl. Airport (STL) to Boulder, CO (WBU-Boulder Municipal) last-minute?
Last-minute bookings from STL to WBU are typically more expensive. To lock in the cheapest rates, start searching for flights as soon as possible. That being said, if you're flexible with your travel dates, you may land a cheap fare right before you leave.
Is it cheaper to book a STL to WBU flight and hotel package?
Opting for a STL to WBU flight and hotel package is usually cheaper than booking separately. With Expedia, you can enjoy the convenience of organizing your trip all in one place. Select from our extensive range of hotels and then add car rentals, flights and activities to your booking. Bundle everything together, and you could save hundreds of dollars.
Can I cancel or change the date of my flight from Lambert-St. Louis Intl. Airport (STL) to Boulder, CO (WBU-Boulder Municipal)?
In most instances, you're able to cancel or reschedule your STL to WBU flight. However, there may be additional fees, especially if you made your booking over 24 hours ago. Check your itinerary for the airline's fees and guidelines on flight changes, or if you'd like further information, go to our Customer Service portal.

Travel information

Origin airport
Lambert-St. Louis Intl.
Destination airport
Boulder Municipal
Distance
797 mi

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St. Louis to Boulder Flights

The cheapest times to fly from St. Louis to Boulder

On average, Thursday can be the cheapest time to fly, according to data from the Airlines Reporting Corporation (ARC), one of the world's biggest databases for global airline sales. The data reveals that you could save up to 16% by flying on a Thursday—the cheapest day to travel on average—instead of a Sunday—the most expensive. Some of the most affordable flights from St. Louis to Boulder are during the month of . You can find some of the cheapest flights from St. Louis to Boulder with Expedia's search tool and vast selection of airlines.

 

The best time to book a flight from St. Louis to Boulder

Sunday is one of the best days to book for cheap flights from St. Louis to Boulder: Tickets reserved on a Sunday cost between 6% and 13% less than those reserved on a Friday, according to ARC data. The data also suggests booking early can also lead to cheaper airfares. You could save 24% by buying your tickets for domestic flights at least a month in advance and 10% by booking international flights 2 months in advance.

 

How to find cheap round-trip tickets from St. Louis to Boulder

Being flexible with your dates and using Expedia's Price Drop Protection and Price Tracking features are some of the best ways of finding a cheap ticket from St. Louis to Boulder in 2025. You can also book with separate airlines for your outbound and return journeys, from one-way. Expedia also offers Price Drop Protection, so if the cost of your airfare goes down after booking, you'll receive a credit for the difference*. This is available for a small fee, and is free to One Key Gold and Platinum tier members.

 

Expedia's Price Tracking feature means you can stay on top of airfares without manually checking every day. It sends you automated price alerts for cheap St. Louis to Boulder flights and uses historical data to indicate when the best time to book is. Download Expedia's free app to activate this handy tool in a few easy taps.

 

You could also save big by booking one of Expedia's vacation packages. Bundling together your St. Louis to Boulder airfare with your accommodations and car rental is often cheaper than booking everything separately. There’s also One Key, Expedia's generous rewards program. Join for free and you could earn One Key cash on most bookings to save on future adventures.

 

*Terms apply.

 

Disclaimer: ARC The statistics are based on average round-trip ticket prices between January and August 2023. The percentages you see are averages.

 

St. Louis to Boulder Flights

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