Question 1

How popular is this Seattle to Boulder flight route?

Accepted Answer

Flights from Seattle/Tacoma Intl to Boulder have been viewed 196 times in the past calendar month.

Question 2

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

Accepted Answer

To fly one-way, consider booking your trip with Frontier, which is currently one of the cheapest options available, starting at $29. Delta flights start at $58 while deals on United Airlines start at $60 one-way.

Question 3

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

Accepted Answer

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

Question 4

Weekly flight availability from Seattle to Boulder

Accepted Answer

The most flights from SEA to BD9 are scheduled on a Saturday (31 on average). You will have fewer flight options on Tuesday, which is when the least amount of flights are scheduled (8 on average).

Question 5

E

Accepted Answer

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.

Question 6

E

Accepted Answer

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).

Question 7

What are the cheapest flights from Seattle to Boulder?

Accepted Answer

Looking for the cheapest flight from Seattle to Boulder? While on average our users pay $679, our data indicates the cheapest price to be $107. The most popular route (Seattle/Tacoma Intl - Denver Intl), is priced around $173.

Question 8

What are the most reliable airlines from Seattle to Boulder?

Accepted Answer

Before booking your flight to Boulder from Seattle, check out the most reliable airlines to get you to your destination on time: American Airlines (100%), Alaska Airlines (88%), Japan Airlines( 86%).

Question 9

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

Accepted Answer

Frontier, Alaska Airlines and Delta are the most popular airlines when flying from Seattle to Boulder.

Question 10

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

Accepted Answer

Unlike in the morning, when flights are generally more expensive, you can save up to 33% on flights from Seattle to Boulder by exploring options for tickets in the evening.

Question 11

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

Accepted Answer

Seattle/Tacoma Intl (SEA) is the airport you will fly out of if you book a flight from Seattle to Boulder. You should not have trouble finding flights to Boulder from Seattle/Tacoma Intl; the airport handles an average of 18 outbound flights to Boulder per day. You should also have plenty of airline options to choose from since 6 airlines have flights from the Seattle airport to Boulder. It is only a 11.4 mi journey to Seattle/Tacoma Intl (SEA) from Seattle’s city center.

Question 12

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

Accepted Answer

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

Question 13

How can I find direct flights from Seattle to Boulder?

Accepted Answer

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

Question 14

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

Accepted Answer

Yes. Cheapflights offers flight deals from Seattle 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.

Most accurate provider	FlightHub 3 stars
Most trusted provider	FlightHub 3 stars
Popular in	June
Cheapest in	January
Average price	$293

Airline	Cheapest	Average	Flexibility	On-time
Frontier	Cheapest$56	Average$210	FlexibilityNo cancel fee	On-time62%
Delta	Cheapest$97	Average$301	FlexibilityNo cancel fee	On-timeN/A
Alaska Airlines	Cheapest$120	Average$319	FlexibilityNo cancel fee	On-time75%
Southwest	Cheapest$135	Average$376	FlexibilityNo cancel fee	On-time63%
United Airlines	Cheapest$143	Average$370	FlexibilityNo cancel fee	On-time69%
JetBlue	Cheapest$143	Average$313	FlexibilityNo cancel fee	On-time62%

Cheap flights from Seattle (SEA) to Boulder, CO

Find cheap flights from Seattle 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 Seattle 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 SEA to BD9?

Unlike in the morning, when flights are generally more expensive, you can save up to 33% on flights from Seattle to Boulder by exploring options for tickets in the evening.

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

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

Weekly flight availability from Seattle to Boulder

The most flights from SEA to BD9 are scheduled on a Saturday (31 on average). You will have fewer flight options on Tuesday, which is when the least amount of flights are scheduled (8 on average).

Reviews of airlines servicing Boulder

See what other customers who have flown with Southwest,Alaska Airlines, andDelta from Seattle to Boulder have to say. You can also see how each airline compares in terms of entertainment options, comfort, food, crew/service, and boarding process.

Related info for your journey

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

How popular is this Seattle to Boulder flight route?

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

What are the most reliable airlines from Seattle to Boulder?

What are the cheapest flights from Seattle to Boulder?

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

How can I find direct flights from Seattle to Boulder?

Can I find deals for business class flights from Seattle 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 Seattle to Boulder

See prices for flight routes from nearby airports that may be better suited for you.

Complete your trip

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

Search flights from Seattle to Boulder by cabin class

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

Seattle and Boulder flights

Browse other Seattle and Boulder flight options. Last updated on November 8, 2026.

Other flights from Seattle

Browse through other flights departing from Seattle. Flights are based on user searches made on Cheapflights and were last updated on November 8, 2026.

Popular flight searches

Check out other popular destinations found by fellow travelers in 2026

Seattle to Boulder flights

Consider these flights traveling from Seattle to Boulder.

Top 6 airlines flying from Seattle to Boulder

100% Free

Book with Flexibility

Travel Smart