How popular is this Portland to Boulder flight route?

Within the past month, 111 users have taken a look at flights from Portland to Boulder.

What are the cheapest airlines to fly from Portland to Boulder one-way?

To fly one-way, consider booking your trip with Frontier, which is currently one of the cheapest options available, starting at $40. Alaska Airlines flights start at $78 while deals on Delta start at $78 one-way.

Weekly flight availability from Portland to Boulder

The most flights from PDX to BD9 are scheduled on a Tuesday (13 on average). You will have fewer flight options on Sunday, which is when the least amount of flights are scheduled (6 on average).

In terms of precipitation, rainfall in Boulder ranges from 0.5 - 2.3 inches per month. May is typically the wettest month, when rainfall can reach 2.3 in. January is typically the driest time to visit Boulder when rainfall is around 0.5 in.

If weather is an important factor for your trip to Boulder, 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 73.4 F. Travelers looking to avoid the cold should look outside of January, when temperatures are typically at their lowest (around 30.2 F).

What are the cheapest flights from Portland to Boulder?

Looking for the cheapest flight from Portland to Boulder? While on average our users pay $943, our data indicates the cheapest price to be $113. The most popular route (Portland - Denver Intl), is priced around $223.

What are the most reliable airlines from Portland to Boulder?

Consider Sun Country Air (100%), Frontier (92%) or Volaris (92%) when booking your flight. These represent the most reliable airlines when flying from Portland to Boulder.

What are the most popular airlines that fly from Portland to Boulder?

When booking a flight from Portland to Boulder, you may want to consider flying on United Airlines, Frontier or Alaska Airlines as they are the most popular for this route.

What airport do you fly from for flights from Portland to Boulder?

Most people fly from Portland (PDX) if they book a flight from Portland to Boulder. On average, Portland has 9 outbound flights to Boulder per day from 6 airlines. Portland is conveniently located just 6.0 mi from Portland’s city center.

Can I find deals for flights from Portland to Boulder that include hotel bookings?

Yes. In addition to deals on Portland to Boulder flights, Cheapflights offers vacation packages that include both flights and hotel.

How can I find direct flights from Portland to Boulder?

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

Can I find deals for business class flights from Portland to Boulder?

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

Find Cheap Flights from Portland to Boulder

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1. Tell us where you want to go

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Cheapflights Tip: The best prices from Portland to Boulder are usually found in January or April, booked 77 days in advance, depart on a Thursday or Friday and return on a Saturday

Find flight deals from Portland to Boulder

Most accurate provider	FlightHub 3 stars
Most trusted provider	FlightHub 3 stars
Popular in	October
Cheapest in	January
Average price	$309

Provider with most accurate pricing for Portland-Denver Intl flight deals.

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Provider most trusted by Cheapflights users for Portland-Denver Intl flights.

Search Deals

Highest demand for flights based on searches. 11% potential increase in price ($37 potential increase over avg. RT price).

Search Deals

Cheapest flight prices on average. 1% potential price decrease ($5 potential savings vs. average RT price).

Search Deals

Average for round-trip flights in November 2026

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Cheapflights Insights

Everything you need to know about your flight from Portland to Boulder

Prices

Airlines

What is the cheapest time of day to fly from PDX to BD9?

Unlike in the morning, when flights are generally more expensive, you can save up to 19% on flights from Portland to Boulder by exploring options for tickets in the afternoon.

What is the cheapest day to fly from Portland to Boulder?

Travelers seeking maximum savings on their Portland to Boulder flight should consider departing on Thursday evenings when fares are most often at their lowest. Sunday evenings flights should be avoided if possible as fares are typically the most expensive at this time.

Reviews of airlines servicing Boulder

Read through reviews of airlines operating flights from Portland to Boulder, such as Southwest,Alaska Airlines, andUnited Airlines. Reviews also offer insight into each airline's entertainment options, comfort, food, crew/service, and boarding process.

Southwest

8.0

Very good

4,214 reviews

Reviews

1 / 20

2.0

Mediocre

Thomas,Dec 2025

SEA - DEN

Plane two hours late in leaving 1:00 pm west coat time got home next day at 2:45am most car rental places are closed and don’t open till 5am

Southwest

8.0

Very good

4,214 reviews

Southwest

8.0

Very good

4,214 reviews

Reviews

1 / 20

2.0

Mediocre

Thomas,Dec 2025

SEA - DEN

Plane two hours late in leaving 1:00 pm west coat time got home next day at 2:45am most car rental places are closed and don’t open till 5am

Alaska Airlines

7.9

Good

13,142 reviews

Southwest

8.0

Very good

4,214 reviews

Reviews

1 / 20

2.0

Mediocre

Thomas,Dec 2025

SEA - DEN

Plane two hours late in leaving 1:00 pm west coat time got home next day at 2:45am most car rental places are closed and don’t open till 5am

United Airlines

7.3

Good

10,462 reviews

Southwest

8.0

Very good

4,214 reviews

Reviews

1 / 20

2.0

Mediocre

Thomas,Dec 2025

SEA - DEN

Plane two hours late in leaving 1:00 pm west coat time got home next day at 2:45am most car rental places are closed and don’t open till 5am

JetBlue

7.1

Good

3,065 reviews

Southwest

8.0

Very good

4,214 reviews

Reviews

1 / 20

2.0

Mediocre

Thomas,Dec 2025

SEA - DEN

Plane two hours late in leaving 1:00 pm west coat time got home next day at 2:45am most car rental places are closed and don’t open till 5am

Frontier

5.5

Fair

2,511 reviews

Southwest

8.0

Very good

4,214 reviews

Reviews

1 / 20

2.0

Mediocre

Thomas,Dec 2025

SEA - DEN

Plane two hours late in leaving 1:00 pm west coat time got home next day at 2:45am most car rental places are closed and don’t open till 5am

Related info for your journey

What airport do you fly from for flights from Portland to Boulder?
Most people fly from Portland (PDX) if they book a flight from Portland to Boulder. On average, Portland has 9 outbound flights to Boulder per day from 6 airlines. Portland is conveniently located just 6.0 mi from Portland’s city center.
How popular is this Portland to Boulder flight route?
Within the past month, 111 users have taken a look at flights from Portland to Boulder.
What are the cheapest airlines to fly from Portland to Boulder one-way?
To fly one-way, consider booking your trip with Frontier, which is currently one of the cheapest options available, starting at $40. Alaska Airlines flights start at $78 while deals on Delta start at $78 one-way.
What are the most reliable airlines from Portland to Boulder?
Consider Sun Country Air (100%), Frontier (92%) or Volaris (92%) when booking your flight. These represent the most reliable airlines when flying from Portland to Boulder.
What are the cheapest flights from Portland to Boulder?
Looking for the cheapest flight from Portland to Boulder? While on average our users pay $943, our data indicates the cheapest price to be $113. The most popular route (Portland - Denver Intl), is priced around $223.
Can I find deals for flights from Portland to Boulder that include hotel bookings?
Yes. In addition to deals on Portland to Boulder flights, Cheapflights offers vacation packages that include both flights and hotel.
How can I find direct flights from Portland to Boulder?
After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from Portland to Boulder.
Can I find deals for business class flights from Portland to Boulder?
Yes. Cheapflights offers flight deals from Portland to Boulder by cabin class. In addition to browsing deals, you can also filter by cabin class on the search results page after making a search.

See more FAQs

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Top 6 airlines flying from Portland to Boulder

Airline	Cheapest	Average	Flexibility	On-time
Frontier	Cheapest$56	Average$210	FlexibilityNo cancel fee	On-time62%
Delta	Cheapest$88	Average$275	FlexibilityNo cancel fee	On-timeN/A
JetBlue	Cheapest$126	Average$279	FlexibilityNo cancel fee	On-time62%
Alaska Airlines	Cheapest$147	Average$291	FlexibilityNo cancel fee	On-time75%
Southwest	Cheapest$157	Average$393	FlexibilityNo cancel fee	On-time63%
United Airlines	Cheapest$157	Average$391	FlexibilityNo cancel fee	On-time69%

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Cheap flights from Portland (PDX) to Boulder, CO

Find cheap flights from Portland to Boulder with Cheapflights

1. Tell us where you want to go

2. Select your favorite providers

3. Compare prices and book

Find flight deals from Portland to Boulder

Most accurate provider

Most trusted provider

Popular in

Cheapest in

Average price

Cheapflights Insights

What is the cheapest time of day to fly from PDX to BD9?

Unlike in the morning, when flights are generally more expensive, you can save up to 19% on flights from Portland to Boulder by exploring options for tickets in the afternoon.

What is the cheapest day to fly from Portland to Boulder?

Travelers seeking maximum savings on their Portland to Boulder flight should consider departing on Thursday evenings when fares are most often at their lowest. Sunday evenings flights should be avoided if possible as fares are typically the most expensive at this time.

Weekly flight availability from Portland to Boulder

The most flights from PDX to BD9 are scheduled on a Tuesday (13 on average). You will have fewer flight options on Sunday, which is when the least amount of flights are scheduled (6 on average).

Reviews of airlines servicing Boulder

Read through reviews of airlines operating flights from Portland to Boulder, such as Southwest,Alaska Airlines, andUnited Airlines. Reviews also offer insight into each airline's entertainment options, comfort, food, crew/service, and boarding process.

Related info for your journey

What airport do you fly from for flights from Portland to Boulder?

How popular is this Portland to Boulder flight route?

What are the cheapest airlines to fly from Portland to Boulder one-way?

What are the most reliable airlines from Portland to Boulder?

What are the cheapest flights from Portland to Boulder?

Can I find deals for flights from Portland to Boulder that include hotel bookings?

How can I find direct flights from Portland to Boulder?

Can I find deals for business class flights from Portland to Boulder?

Browse thousands of different options on Cheapflights for your next trip

Toggle through the tabs below to find thousands of options on Cheapflights for your next trip.

Alternative routes for Portland to Boulder

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Complete your trip

Complete your trip to Boulder by adding a car rental and/or hotel reservation to your travel itinerary.

Search flights from Portland to Boulder by cabin class

Find flights from Portland to Boulder, based on your preferred cabin class, be it economy, premium economy, business, or first class.

Portland and Boulder flights

Browse other Portland and Boulder flight options. Last updated on November 4, 2026.

Other flights from Portland

Browse through other flights departing from Portland. Flights are based on user searches made on Cheapflights and were last updated on November 4, 2026.

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Portland to Boulder flights

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Top 6 airlines flying from Portland to Boulder

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