$47 Find Cheap Flights from Washington, D.C. to Boulder

This is the cheapest one-way flight price found by a KAYAK user in the last 72 hours by searching for a flight from Washington, D.C. to Boulder departing on 3/7. Fares are subject to change and may not be available on all flights or dates of travel. Click the price to replicate the search for this deal.
1 adult
1 adult, Economy, 0 bags

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Everything you should know

Cheapest round-trip
$100
Overall average: $260
Frontier
Wed 3/11Mon 3/16
DCA - DEN • Non-stop
Cheapest one-way
$47
Typical prices: $134-$301
Frontier
Sat 3/7
BWI - DEN • 1 stop
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Flight Deals
Useful Info
Flight Deals

Cheap Flights from Washington, D.C. to Boulder (WAS-DEN)

 
Here are some of the best deals found on KAYAK recently from the most popular airlines for round-trip flights from Washington, D.C. to Boulder that are departing in the next months. While these flights were available on KAYAK in the last 72 hours, prices and availability are subject to change and deals may expire.
Discover the best prices for you by selecting your travel dates on KAYAK.

Recent round-trip flight deals from Washington, D.C. to Boulder

Wed, Mar 11 - Mon, Mar 16
Frontier Logo
6:00 pm - 8:16 pm
DCA
-
DEN
4h 16mnonstop
Frontier Logo
11:37 am - 4:59 pm
DEN
-
DCA
3h 22mnonstop
$100Frontier
Wed, Feb 25 - Wed, Feb 25
Frontier Logo
8:00 am - 10:22 am
DCA
-
DEN
4h 22mnonstop
Frontier Logo
1:39 pm - 6:59 pm
DEN
-
DCA
3h 20mnonstop
$103Frontier
Sat, Feb 28 - Sat, Mar 7
Frontier Logo
10:29 am - 9:35 pm
IAD
-
DEN
13h 06m
1 stop
Frontier Logo
8:50 am - 12:31 am
DEN
-
IAD
13h 41m
1 stop
$106Frontier
Fri, Feb 27 - Mon, Mar 2
Frontier Logo
6:00 pm - 8:16 pm
DCA
-
DEN
4h 16mnonstop
Frontier Logo
7:33 am - 1:00 pm
DEN
-
DCA
3h 27mnonstop
$107Frontier
Sat, Feb 21 - Tue, Feb 24
Frontier Logo
8:00 am - 10:22 am
DCA
-
DEN
4h 22mnonstop
Frontier Logo
7:48 am - 1:15 pm
DEN
-
DCA
3h 27mnonstop
$108Frontier
Sun, Feb 22 - Wed, Feb 25
Frontier Logo
8:00 am - 10:22 am
DCA
-
DEN
4h 22mnonstop
Frontier Logo
1:39 pm - 6:59 pm
DEN
-
DCA
3h 20mnonstop
$111Frontier
Tue, Mar 10 - Fri, Mar 13
Frontier Logo
8:00 am - 10:22 am
DCA
-
DEN
4h 22mnonstop
Frontier Logo
7:35 am - 1:02 pm
DEN
-
DCA
3h 27mnonstop
$112Frontier
Thu, Mar 5 - Tue, Mar 10
Frontier Logo
2:00 pm - 4:22 pm
DCA
-
DEN
4h 22mnonstop
Frontier Logo
7:35 am - 1:02 pm
DEN
-
DCA
3h 27mnonstop
$113Frontier
Sat, Feb 28 - Wed, Mar 4
Multiple Airlines Logo
10:29 am - 9:35 pm
IAD
-
DEN
13h 06m
1 stop
Multiple Airlines Logo
2:19 pm - 10:33 am
DEN
-
IAD
18h 14m
2 stops
$143Multiple Airlines
Wed, Feb 18 - Fri, Feb 20
Multiple Airlines Logo
12:30 pm - 7:02 am
BWI
-
DEN
20h 32m
2 stops
Multiple Airlines Logo
9:00 pm - 10:27 am
DEN
-
BWI
11h 27m
1 stop
$218Multiple Airlines
Useful Info

Good to know

Low seasonNovember
Cheapest flight$47
Best time to beat the crowds with an average 3% drop in price.
Most popular time to fly and prices are also 7% lower on average.
Flight from Baltimore to Denver

When to book flights from Washington, D.C. to Boulder

Are your dates flexible? Find out the best times to travel from Washington, D.C. to Boulder based on our flight data from the last year. Discover the cheapest month and even day to fly.
Estimated round-trip price

FAQs for booking flights from Washington, D.C. to Boulder

  • Which airports will I be using when flying from Washington, D.C. to Boulder?

    When flying out of Washington, D.C. you’ll be using one of these airports: Washington, D.C. Reagan-National or Washington, D.C. Dulles Intl. Boulder does not have its own airport so you’ll be flying into nearby Denver Intl airport, which is 33.4 mi away.

  • How long does a flight from Washington, D.C. to Boulder take?

    Direct flights cover the 1,471 miles separating Washington, D.C. and Boulder in about 3h 55m.

  • How many flights are there between Washington, D.C. and Boulder?

    39 direct flights run between Washington, D.C. and Boulder on a daily basis. On average, there are about 277 departures each week.

  • What’s the cheapest day of the week to fly between Washington, D.C. and Boulder?

    Consider leaving on a Tuesday and avoid Saturdays if you are looking for the best rates. For your return to Washington, D.C., you’ll find the best rates on Tuesdays and the most expensive ones on Saturdays.

  • How does KAYAK find such low prices on flights from Washington, D.C. to Boulder?

    KAYAK is a travel search engine. That means we look across the web to find the best prices we can find for our users. With over 2 billion flight queries processed yearly, we are able to display a variety of prices and options on flights from Washington, D.C. to Boulder.

  • How does KAYAK's flight Price Forecast tool help me choose the right time to buy my flight ticket from Washington, D.C. to Boulder?

    KAYAK’s flight Price Forecast tool uses historical data to determine whether the price for a flight to Boulder from Washington, D.C. is likely to change within 7 days, so travelers know whether to wait or book now.

  • What is the Hacker Fare option on flights from Washington, D.C. to Boulder?

    Hacker Fares allow you to combine one-way tickets in order to save you money over a traditional round-trip ticket. You could then fly to Boulder with an airline and back to Washington, D.C. with another airline.

  • What is KAYAK's "flexible dates" feature and why should I care when looking for a flight from Washington, D.C. to Boulder?

    Sometimes travel dates aren't set in stone. If your preferred travel dates have some wiggle room, flexible dates will show you all the options when flying to Boulder from Washington, D.C. up to 3 days before/after your preferred dates. You can then pick the flights that suit you best.

  • Which airlines provide the cheapest flights from Washington, D.C. to Boulder?

    In the last 72 hours, the cheapest one-way ticket between Washington, D.C. and Boulder found on KAYAK was with Frontier for $58. Frontier offered a round-trip connection from $82 and American Airlines from $166.

Top tips for finding cheap flights from Washington, D.C. to Boulder

  • There is no airport in Boulder. Instead, you’ll be flying into Denver Airport when flying between Washington, D.C. and Boulder.
  • The cheapest flight from Washington, D.C. to Boulder was found 35 days before departure, on average.
  • Book at least 1 week before departure in order to get a below-average price.
  • High season is considered to be November, December and January. The cheapest month to fly is February.

Reviews of the top 5 airlines serving Washington, D.C. to Boulder

 
Need help choosing which airline to fly with from Washington, D.C. to Boulder? KAYAK airline reviews give an overall score for each airline based on loads of factors, including comfort, boarding, in-flight entertainment and more, to make your decision easier. See airline scores according to verified KAYAK customer reviews.
8.0
SouthwestOverall score based on 4267 reviews
8.6Crew
7.5Entertainment
8.0Comfort
8.1Boarding
7.0Food
Airline reviews

All good except once again bags took an hour at Midway Airport Happens all the time. Ridiculous

10.0 ExcellentAnonymous, Jan 2026
PHX - MDW
Read more Southwest reviews

All good except once again bags took an hour at Midway Airport Happens all the time. Ridiculous

Everything went smoothly and we even arrived a little bit early.

Great vacation. Can't wait till next year for another one.

Great flight but super high price. Glad it was a business trip and not personal

On time. Friendly staff. Took to long to pre bord all the specialty groups. Cramped small plane

The seats were comfortable, and the boarding process was pretty smooth.

3 hour delay. Had to change plans and was still delayed.

The staff was very friendly, professional, and courteous. The overall flight was a great experience.

The crew canceled the complementary snack and drink in anticipation of turbulence that never materialized. I was counting on the drink (water) to take the the doses of medication - prescribed for my heart condition - that were due during the flight. Since no snack or meal was served on this flight, I cannot rate the food quality. Otherwise, this flight was excellent.

Departure was delayed more than 1/2 hour while we waited for luggage (only) transfer from another flight/plane. Once approved for takeoff, the flight was excellent.

Timing, quality of service, promptness and courtesy of the staff

It was last minute due to weather - considering - it was amazing! Good smiles, friendly staff and they were making sure we knew what was going on when and where.

delta last minute gave me a boarding pass for a different flight with no confirmation that they were changing it

The service from the flight attendants were of supreme quality. They greeted and treated everyone with a wide smile. This is totally absent nowadays. Kudos to them!!!!

Excellent flight and got us around tough weather. Only issue was seat TV did not work and crew tried to reboot.

Very large passenger too space from my own seat. Arm board couldn’t be lowered because of his size. It wads very uncomfortable trip, as the flight was full couldn’t move anywhere having back pain because of the position in which I was the entire flight.

was sitting in the jet bridge for 10 minutes in -20 degree weather waiting for my bag

Outdated equipment in disrepair, wifi inoperable. Broken seats, taped air vents, generally poor condition, the 717 showed its age and lack of upkeep.

My flight out of Baton Rouge to Atlanta was delayed by a half hour. This got us into Atlanta airport 30 minutes late. I ran through the airport to get to my connecting flight. As I approached the boarding gate, I saw the boarding door was still open and a passenger was being checked in. But when I got to the gate, the boarding agent told me they had already given away my seat and there were no empty seats on that flight. So I had to take a later flight. That has never happened to me before. Very frustrating.

Connection through Atlanta was difficult. Mechanical issue on plane caused a two hour delay. New gate was a mile away.

Very good. Because of the delays with my previous flight, I missed my connection, but I was able to book another flight through the United app easily.

Was happy we finally got upgraded in 1st class. The seat getting old. The cushiness need some improvement.

Ineffective communication with United resulted in lost baggage. Their Baggage Tracing counter at MUC was shut down from 11:00-14:15 on my arrival. Undertrained, underinformed staff had me Running all over MUC to find someone to help me to no avail. Staff was rude, unhelpful, and unable to effectively use the systems they did have operational. They refused to contact United in any way or provide any accommodation or other resources while I waited for my luggage. This has destroyed my downstream itinerary. If they had even the slightest visibility I may have been able to reschedule/plan, but again, their staff provided nothing, and did nothing more than their website, which doesn’t even work on a standard phone browser. Miserable failure at all levels that weren’t associated with the operation of the aircraft.

Sat next to a one year old. She crawled all over the place and made me laugh.

The Crew and the food was the worst I ever had in Business Class. First they told us there were no space for carry on. It was plenty of space over our 2 row seats, we had to ask to let us travel with it which was accepted. They were aware that we had to run for the connection due to the previous flight delay. Have us one hour waiting for more customers and not even offer a glass of water. Then started the service and they started to serve other passengers drinks in business and did not offer any drinks until they serve our pre ordered meal and I ask for something to drink. I had to wait until they finished to serve all passengers until Inget something. The crew was the worts I ever had for Business Class in my life.

Not great experience - we were super late boarding due to issues with aircraft. Then when we finally all got onboard and seated and they started taxiing out to the runway they just stopped then turned around and went back to the airport. Apparently the crew “ran out of time” to legally fly us. They mentioned that they were about 2 minutes away from taking off. I understand the rules and safety but kinda wonder why they would have bothered boarding us in the first place? Had to go all the way back and de plane and then wait in a HUGE line to get a hotel (this is somewhere around 2:30am) finally got to hotel by Uber (no shuttle after 20min so gave up) and they ended up putting us all back on the same aircraft at 10am next morning so got about 2.5 hours sleep. They did give us. $250 credit, but it was a São Paulo Brazil flight out of Dulles. The flight and everything was fine.

Starlink wifi on the Embraer E175 is an excellent experience. I was able to connect and work from IAD all the way to approach into BTV.

7 hours delayed due to operational issues on United’s end. Basically laziness.

Short flight but an "eager to help" crew made the journey more enjoyable!

During booking, I kept trying submitting my payment from the Mexican website and it didn't work. After I had the idea to change it to the Canadian website, it worked but I had to be charged the equivalent of 50 CAD more. I received the clear instruction that I would only be able to check-in at the airport and that it was impossible to select a seat 24 hours before departure, that I had to pay 144 CAD to do so, although not only was I able to check-in 24 hours before departure, but I could have selected my seats for free then. All in all, I almost threw $200 out the window due to misleading information. Besides, the app kept crashing, the information to get to the gate on the app was inaccurate, my gate was switched and I was only informed once in the air (luckily I had noticed the departure pannel), I was not addressed in my language beforehand and even if I tried I was immediately answered in English (which meant the crew understood but didn't want to answer accordingly), there was only one snack & beverage service on my medium haul flight and no beverage service on my short haul flight. To be fair, the planes were comfortable, the crew apart from the language issue was helpful, dynamic and engaging, the plane was clean and the directions were clear and direct. United has a lot of potential to be one of my favourite airlines, but the devil is in the details and a lot of them missed the target.

Don't change gate multiple times make people run across the airport. Announce delays in a timely manner. Have maintenance crew ready. Don't delay and keep passengers on the plane for 3 hrs. on tarmac.

It was a little concerning to hear the ground crew arguing with the flight crew over baggage space. Instead of taking them and checking them, they started checking for space in the first class cabin moving items around like the flight crew didn't know what they were doing. I was embarrassed for them.

My seat tv didn’t work the whole trip. And the seat space is too small despite being seated at the front.

delayed due to weather. Could not communicate with family since the wifi was broken

I got sick nothing contagious but distressing and the care I received by Kayla? Keighly the flight attendant will be memorable for ever. Thank You

We were told the flight was delayed 5 times, then it was moved to the next day.

Flight delay was communicated before leaving for airport which caused it to be a non-event. Great flight and crew!

The flight attendant, a black woman with curly hair who sat near Row 21, was wonderful and kind.

Flight was delayed leaving Dallas. Arrived about 2 hours later than scheduled.

We were delayed for a “couple of maintenance issues.” They were resolved rather quickly but a computer glitch caused someone in the airport to have to bring a physical copy of the paperwork so we could leave. I don’t know where they had to drive from to get to our plane but it took forever & we were 1 1/2 hrs late in leaving. The flight itself was fine.

It was costly and difficult to check in. $85 to take a small suitcase with me, carry on or checked and $75 on the return trip, Plus $25 if I didn't check my self in check in $25, because I couldn't do it on the kiosk. Small very uncomfortable seats, waited on the runway for near an hour each way. It was my worst flight to date.

Due to weather, my flight was delayed, further delayed, then canceled. I eventually got through to a support person who helped me find a different route out of MSP, but to get to DIA, they didn't want to, but eventually did help with the connection ticket purchase. But even this replacement flight was delayed time and time again, and I would have missed my connecting flights and I didn't want to get stuck in a layover city, so after 12 hours at the airport with two young boys who were very tired, we just cancelled our plans and spent the week at home, instead of Nana's.

I knew going into this that Frontier, being a low cost carrier, would be pretty bare bones and charge for most extras but this was made up for by the fact that the airplane was a reasonably new Airbus, every employee was great and best of all, Everett Washington is an amazing airport - thanks Frontier for flying there!!!

Seats were new and comfortable. Staff was fine. Missed my connection due to weather -which wasn’t their fault- but got no help at all. Gate staff sent me to customer service, which was and stayed unstaffed. Sign with QR code directed me to call or chat. Chat was useless. Call was returned after an hour. No itinerary offered by Frontier could get me home in less than 30 hours. Rebooked with another airline and got a partial refund that came to about 10 percent of what I paid to get home.

The experience was good. No frills but I got there safe and sound and on time.

As every law enforcement agency I could imagine surrounded the plane and we didn’t disembark for 2 hours and then had to stick around for another hour to go get our personal belongings after leaving them behind and being bused away from the plane, it was scary and inconvenient. We were given no information as to why this was happening. Lack of communication with passengers was disappointing.

Frontier Airlines was AWFUL. I was an hour early for my flight and the lady refused to check me in. I had to purchase a whole new ticket with a different airline.

Late, terrible communication, horrible planning of passenger seating until the literal last minute. One of the worst flying experiences of my life. Y'all suck

First of all, we never got on the connecting flight to Denver. They delayed our flight for two hours. If we would have gotten on that flight, we would have been stuck in Denver for 13 hours. So we re- routed our flight for a straight through flight to Oklahoma two days later. THEN, they delayed that flight for two hours. After that we were able to finally get on our flight and come home. Frontier Airlines - one of the worst airlines I have ever been on.

Terrible communication with weather delay, lost baggage, near impossible to reach customer service

Everything you need to know for your flight from Washington, D.C. to Boulder

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