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Dulles Intl

$109+ Cheap flights from Colorado to Dulles Intl (IAD)

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 6/14. Fares are subject to change and may not be available on all flights or dates of travel.
DEN — IAD
May 5 — May 121
Mon 5/5
Mon 5/12
1 adult, Economy
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Cheap flight deals from Colorado to Dulles Intl

Keep the following information in mind while searching for Colorado to Dulles Intl flight deals. Data was last updated April 30, 2025.

Most accurate provider

Mytrip
3 stars

Most trusted provider

Mytrip
3 stars

Round-trip from

$217
(United Airlines)

One-way from

$109
(Southwest)

Popular in

December

Cheapest in

September

Average price

$258

Good round-trip deal

$331 or less

Good one-way deal

$180 or less
Provider with most accurate pricing for Denver Intl-Washington, D.C. (WAS) flight deals.
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Provider most trusted by Cheapflights users for Denver Intl-Washington, D.C. (WAS) flights.
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From Colorado to Washington, D.C. Dulles Intl
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One-way flight from Colorado to Washington, D.C. Dulles Intl
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Highest demand for flights based on searches. 7% potential increase in price ($21 potential increase over avg. RT price).
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Cheapest flight prices on average. 1% potential price decrease ($4 potential savings vs. average RT price).
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Average for round-trip flights in April 2025
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Price to beat on a round-trip flight from Colorado to Washington, D.C. Dulles Intl.
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Price to beat on a one-way flight from Colorado to Washington, D.C. Dulles Intl.
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Find flight deals from Colorado to Dulles Intl

Cheapest flights from Colorado to Dulles Intl
Explore the most affordable flight options available from Colorado to Dulles Intl. Find the lowest fares from popular airlines and budget airlines, with prices last updated on April 30, 2025.

This United Airlines deal was found by Cheapflights users on 4/29. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 6/116:00 amDEN - IAD
Nonstop3h 26mUnited Airlines
Wed 6/1110:19 pmIAD - DEN
Nonstop3h 56mUnited Airlines
Deal found 4/29$217
This American Airlines deal was found by Cheapflights users on 4/27. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 6/107:20 amDEN - IAD
1 stop8h 15mAmerican Airlines
Tue 6/106:43 pmIAD - DEN
1 stop7h 01mAmerican Airlines
Deal found 4/27$231
This Delta deal was found by Cheapflights users on 4/28. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 8/710:54 amCOS - IAD
1 stop5h 30mDelta
Wed 8/136:15 amIAD - COS
1 stop6h 29mDelta
Deal found 4/28$237
This Cheapflightsfares deal was found by Cheapflights users on 4/29. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 5/226:54 pmDEN - IAD
1 stop14h 59mSun Country Air
Sun 5/2512:49 pmIAD - DEN
1 stop6h 38mSun Country Air
Deal found 4/29$240
This Southwest deal was found by Cheapflights users on 4/28. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 5/245:50 pmDEN - IAD
Nonstop3h 25mSouthwest
Sat 5/315:05 amIAD - DEN
Nonstop3h 50mSouthwest
Deal found 4/28$243
This Delta deal was found by Cheapflights users on 4/28. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 7/44:10 pmDEN - IAD
1 stop5h 09mDelta
Wed 7/307:04 pmIAD - DEN
1 stop6h 24mDelta
Deal found 4/28$245
This American Airlines deal was found by Cheapflights users on 4/29. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 8/1212:12 pmCOS - IAD
2 stops8h 49mAmerican Airlines
Wed 8/2010:26 amIAD - COS
2 stops9h 54mAmerican Airlines
Deal found 4/29$247
This Frontier deal was found by Cheapflights users on 4/29. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 5/1312:01 amDEN - IAD
1 stop12h 49mFrontier
Tue 5/2011:47 amIAD - DEN
1 stop12h 44mFrontier
Deal found 4/29$250
This Mytrip deal was found by Cheapflights users on 4/28. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 8/105:42 pmDEN - IAD
1 stop18h 41mMultiple Airlines
Thu 8/1412:40 pmIAD - DEN
1 stop7h 21mMultiple Airlines
Deal found 4/28$266
This United Airlines deal was found by Cheapflights users on 4/29. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 6/265:20 pmCOS - IAD
1 stop5h 25mUnited Airlines
Mon 6/302:39 pmIAD - COS
1 stop6h 16mUnited Airlines
Deal found 4/29$281
This United Airlines deal was found by Cheapflights users on 4/28. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 7/162:50 pmASE - IAD
1 stop6h 20mUnited Airlines
Sun 7/206:30 amIAD - ASE
1 stop6h 25mUnited Airlines
Deal found 4/28$287
This United Airlines deal was found by Cheapflights users on 4/28. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 5/217:12 amHDN - IAD
1 stop6h 24mUnited Airlines
Mon 5/268:20 amIAD - HDN
1 stop8h 13mUnited Airlines
Deal found 4/28$298

Cheapflights Fare Finder

Customize your flight search to find flights from Colorado to Dulles Intl that fit within your specific budget. Explore options based on user searches and filter the results based on your desired price range. Find flights that match your budget for a cost-effective journey. Over the last 7 days, Cheapflights users made 2,558,603 searches. Data last updated April 30, 2025.
Use the filters below to find and compare flights from Colorado to Washington, D.C. Dulles Intl Airport that are best for you.

Fly from

Colorado

Fly to

Dulles Intl

Route

Depart

Return

Price

DenverWashington, D.C.

DEN - IAD

DENIAD

Denver Intl

Tue 6/10

8:01 am-1:27 pm

Nonstop3h 26m

Washington, D.C. Dulles Intl

Tue 6/10

7:59 pm-9:55 pm

Nonstop3h 56m

$217

DenverWashington, D.C.

DEN - IAD

DENIAD

Denver Intl

Tue 6/10

7:20 am-5:35 pm

1 stop8h 15m

Washington, D.C. Dulles Intl

Tue 6/10

6:43 pm-11:44 pm

1 stop7h 01m

$231

Colorado SpringsWashington, D.C.

COS - IAD

COSIAD

Colorado Springs

Wed 6/25

6:00 am-4:33 pm

1 stop8h 33m

Washington, D.C. Dulles Intl

Mon 6/30

6:20 am-10:02 am

1 stop5h 42m

$237

DenverWashington, D.C.

DEN - IAD

DENIAD

Denver Intl

Thu 5/22

6:54 pm-11:53 am

1 stop14h 59m

Washington, D.C. Dulles Intl

Sun 5/25

12:49 pm-5:27 pm

1 stop6h 38m

$240

DenverWashington, D.C.

DEN - IAD

DENIAD

Denver Intl

Sat 5/24

5:50 pm-11:15 pm

Nonstop3h 25m

Washington, D.C. Dulles Intl

Sat 5/31

5:05 am-6:55 am

Nonstop3h 50m

$243

DenverWashington, D.C.

DEN - IAD

DENIAD

Denver Intl

Fri 7/4

4:10 pm-11:19 pm

1 stop5h 09m

Washington, D.C. Dulles Intl

Wed 7/30

7:04 pm-11:28 pm

1 stop6h 24m

$245

Colorado SpringsWashington, D.C.

COS - IAD

COSIAD

Colorado Springs

Tue 8/12

12:12 pm-11:01 pm

2 stops8h 49m

Washington, D.C. Dulles Intl

Wed 8/20

10:26 am-6:20 pm

2 stops9h 54m

$247

DenverWashington, D.C.

DEN - IAD

DENIAD

Denver Intl

Tue 5/13

12:01 am-2:50 pm

1 stop12h 49m

Washington, D.C. Dulles Intl

Tue 5/20

11:47 am-10:31 pm

1 stop12h 44m

$250

DenverWashington, D.C.

DEN - IAD

DENIAD

Denver Intl

Sun 8/10

5:42 pm-2:23 pm

1 stop18h 41m

Washington, D.C. Dulles Intl

Thu 8/14

12:40 pm-6:01 pm

1 stop7h 21m

$266

Colorado SpringsWashington, D.C.

COS - IAD

COSIAD

Colorado Springs

Thu 6/26

5:20 pm-12:45 am

1 stop5h 25m

Washington, D.C. Dulles Intl

Mon 6/30

2:39 pm-6:55 pm

1 stop6h 16m

$281

Flights are sorted by cheapest round-trip flights first.

Deals found on 4/28

Showing 1-10 of 53 results
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Best time to book a flight from Colorado to Dulles Intl

Have a flexible travel schedule? Discover the best time to fly to Dulles Intl from Colorado 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 Colorado to Washington, D.C. Dulles Intl Airport

What is the cheapest month to book a flight from Colorado to Washington, D.C. Dulles Intl Airport?

Currently, August is the cheapest month in which you can book a flight from Colorado to Washington, D.C. Dulles Intl Airport (average of $309). Flying from Colorado to Washington, D.C. Dulles Intl Airport in June is currently the most expensive (average of $373). 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 time of day to fly from CO to IAD?

Find hourly flight availability from Colorado to Dulles Intl. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated April 30, 2025.

Regardless of the time of day you decide to fly, the ticket price will remain around the same. Book flights from Colorado to Washington, D.C. Dulles Intl Airport as you normally would.

Weekly flight availability from Colorado to Washington, D.C. Dulles Intl Airport

Explore weekly flight availability from Colorado to Dulles Intl. Discover flights operating on different days of the week, giving you the flexibility to choose a travel day that best fits your plans. Compare info to find the most convenient option for your journey. Data last updated April 30, 2025.

The most flights from USCO to IAD are scheduled on a Wednesday (24 on average). You will have fewer flight options on Saturday, which is when the least amount of flights are scheduled (2 on average).

Rainfall in Dulles Intl by month

Plan your trip to Dulles Intl by taking into account the average rainfall totals by month.

In terms of precipitation, rainfall in Washington, D.C. Dulles Intl Airport ranges from 2.6 - 4.0 inches per month. May is typically the wettest month, when rainfall can reach 4.0 in. February is typically the driest time to visit Washington, D.C. Dulles Intl Airport when rainfall is around 2.6 in.

Temperature in Dulles Intl by month

Plan your trip to Dulles Intl by taking into account the average temperature totals by month.

If weather is an important factor for your trip to Washington, D.C. Dulles Intl Airport, 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 35.6 F).

Reviews of airlines servicing Dulles Intl

Get insights into the airlines that provide service to Dulles Intl. Read reviews, discover amenities, and learn about the overall travel experience offered by airlines. Use this information to make informed decisions when choosing an airline for your flight to Dulles Intl. Reviews last updated April 30, 2025.
See what other customers who have flown with Alaska Airlines, Southwest and Delta from Colorado to Washington, D.C. have to say. Users can see the overall rating for each airline as well as how each is rated in terms of entertainment options, comfort, food, crew/service, and boarding process.
Alaska Airlines
8.0
Very good
9,961 reviews

Food

7.1

Boarding

8.2

Comfort

7.9

Overall

8.0

Crew

8.5

Entertainment

7.1

Reviews

1 / 20
10.0
Excellent

James,Apr 2025

LAX - SFO

Good flight except the uncontrollable cold air from the ceiling.
Alaska Airlines
8.0
Very good
9,961 reviews
Alaska Airlines
8.0
Very good
9,961 reviews

Food

7.1

Boarding

8.2

Comfort

7.9

Overall

8.0

Crew

8.5

Entertainment

7.1

Reviews

1 / 20
10.0
Excellent

James,Apr 2025

LAX - SFO

Good flight except the uncontrollable cold air from the ceiling.
Southwest
8.0
Very good
4,295 reviews
Alaska Airlines
8.0
Very good
9,961 reviews

Food

7.1

Boarding

8.2

Comfort

7.9

Overall

8.0

Crew

8.5

Entertainment

7.1

Reviews

1 / 20
10.0
Excellent

James,Apr 2025

LAX - SFO

Good flight except the uncontrollable cold air from the ceiling.
Delta
8.0
Very good
7,929 reviews
Alaska Airlines
8.0
Very good
9,961 reviews

Food

7.1

Boarding

8.2

Comfort

7.9

Overall

8.0

Crew

8.5

Entertainment

7.1

Reviews

1 / 20
10.0
Excellent

James,Apr 2025

LAX - SFO

Good flight except the uncontrollable cold air from the ceiling.
Hawaiian Airlines
7.9
Good
2,405 reviews
Alaska Airlines
8.0
Very good
9,961 reviews

Food

7.1

Boarding

8.2

Comfort

7.9

Overall

8.0

Crew

8.5

Entertainment

7.1

Reviews

1 / 20
10.0
Excellent

James,Apr 2025

LAX - SFO

Good flight except the uncontrollable cold air from the ceiling.
United Airlines
7.4
Good
8,696 reviews
Alaska Airlines
8.0
Very good
9,961 reviews

Food

7.1

Boarding

8.2

Comfort

7.9

Overall

8.0

Crew

8.5

Entertainment

7.1

Reviews

1 / 20
10.0
Excellent

James,Apr 2025

LAX - SFO

Good flight except the uncontrollable cold air from the ceiling.

Related info for your journey

Find useful and relevant information for your journey from Colorado to Dulles Intl. 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 to fly from Colorado to Washington, D.C. Dulles Intl Airport one-way?

    The cheapest airlines for a one-way flight from Colorado to Washington, D.C. Dulles Intl Airport are Southwest ($109), Allegiant Air ($110), and Delta ($119).

  • What are the most popular routes from Colorado to Washington, D.C. Dulles Intl Airport?

    The most popular route from Colorado to Washington, D.C. Dulles Intl Airport is Denver Intl - Washington, D.C. Dulles Intl. You may also consider Colorado Springs - Washington, D.C. Dulles Intl or Montrose County - Washington, D.C. Dulles Intl.

  • What are the most reliable airlines from Colorado to Washington, D.C. Dulles Intl Airport?

    Consider Avianca (92%), Brussels Airlines (87%) or United Airlines (87%) when booking your flight. These represent the most reliable airlines when flying from Colorado to Washington, D.C. Dulles Intl Airport.

  • What are the cheapest flights from Colorado to Washington, D.C. Dulles Intl Airport?

    Looking at all options, your cheapest flight can be booked for $118. While the most popular route (Denver Intl - Washington, D.C. Dulles Intl) can be booked for $217 on average our data indicates $1,025 when flying from Colorado to Washington, D.C. Dulles Intl Airport.

  • Can I find deals for flights from Colorado to Dulles Intl that include hotel bookings?

    Yes. In addition to deals on Colorado to Dulles Intl flights, Cheapflights offers vacation packages that include both flights and hotel.

  • How can I find direct flights from Colorado to Dulles Intl?

    After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from Colorado to Dulles Intl.

  • Can I find deals for business class flights from Colorado to Dulles Intl?

    Yes. Cheapflights offers flight deals from Colorado to Dulles Intl 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 Colorado to Washington, D.C. Dulles Intl Airport?

    Currently, August is the cheapest month in which you can book a flight from Colorado to Washington, D.C. Dulles Intl Airport (average of $309). Flying from Colorado to Washington, D.C. Dulles Intl Airport in June is currently the most expensive (average of $373). 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

Traveling to a place near Colorado?

Book flights to Colorado if you plan to visit one of these locations
Alexandria
Arlington
Woodbridge
Tysons
Fairfax
Springfield
Rockville
Fredericksburg
Silver Spring
Gaithersburg
Linthicum Heights
Falls Church
Laurel
Easton
Towson
Herndon
Sterling
Bowie
National Harbor
Oxon Hill

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Alternative routes for Colorado to Dulles Intl

See prices for flight routes from nearby airports that may be better suited for you.
Los Angeles to Reagan-National flights
Dallas/Fort Worth to Dulles Intl flights
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Seattle to Dulles Intl flights
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Dallas/Fort Worth to Reagan-National flights
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Fort Lauderdale to Baltimore flights
Midway to Baltimore flights
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John F Kennedy Intl to Dulles Intl flights
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Denver to Dulles Intl flights
John F Kennedy Intl to Reagan-National flights
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LaGuardia to Reagan-National flights
Salt Lake City to Dulles Intl flights
George Bush Intcntl to Baltimore flights
Sky Harbor Intl to Dulles Intl flights
Midway to Dulles Intl flights
Portland to Reagan-National flights
Sky Harbor Intl to Reagan-National flights
Miami to Baltimore flights
Burbank to Baltimore flights
Minneapolis to Reagan-National flights

Top 5 airlines flying from Colorado to Dulles Intl

Discover the top 5 airlines that operate flights from Colorado to Dulles Intl. Compare their services, reliability, and customer satisfaction ratings to choose the airline that best suits your travel preferences and needs. Over the last 7 days, Cheapflights users made 2,558,603 searches. Data last updated April 30, 2025.
AirlineCheapestAverageFlexibilityOn-time
FrontierCheapest$110Average$217FlexibilityNo cancel feeOn-time62%
DeltaCheapest$144Average$342FlexibilityNo cancel feeOn-timeN/A
United AirlinesCheapest$214Average$503FlexibilityNo cancel feeOn-time69%
SouthwestCheapest$218Average$371FlexibilityNo cancel feeOn-time63%
American AirlinesCheapest$228Average$455FlexibilityNo cancel feeOn-time71%

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