What is the cheapest month to fly to Boulder?

Currently, the cheapest month for flights to Boulder is February . The most expensive month for flights is December . The cheapest prices are shown above but prices will vary according to departure times, airlines, class and how early you book.

Can I find cheaper flights to Boulder if I am willing to have stopovers?

Yes, flights with stopovers are often cheaper than direct flights. Keep an eye out for flight deals to Boulder on Cheapflights that require 1 or 2 stops for potential cost savings.

What is the best airline to fly to Boulder?

Based on reviews from Cheapflights users, Qantas Airways is rated the highest out of the airlines that fly to Boulder.

How much is a return flight to Boulder?

A return flight to Boulder will typically cost around $107, however they can be found for as little as $106.

Where does the fastest flight to Boulder depart from?

For those looking to save time traveling to Boulder, Sydney Kingsford Smith offers the quickest one-way flight (20 hours 51 minutes).

Does Denver Intl have car hire?

Yes. Those touching down at Denver Intl can take advantage of the car hire services offered upon their arrival.

Are there hotels close to Denver Intl?

Yes. Denver Intl has hotels nearby for those requiring accommodations. The Westin Denver International Airport is the closest property to Denver Intl (0.0 km away from Denver Intl).

$819+ Cheap Flights to Boulder

Flights to Boulder in 2025

Return from	$1,509
One-way from	$819
Popular in	December
Cheapest in	February
Average price	$1,562

Air New Zealand
20/1-10/3
4 total stops
50h 03m total
Sydney to Denver

Search Deals

15/2
2 total stops
27h 10m total
Sydney to Boulder

Search Deals

Highest demand for flights based on searches. 17% potential increase in price ($341 potential increase over avg. return price).

Search Deals

Cheapest flight prices on average. 4% potential price decrease ($64 potential savings vs. average return price).

Search Deals

Average for return flights in October 2025

Search Deals

Find flight deals to Boulder

Enter your travel dates to find the best prices.

Cheapest flights to Boulder
Explore the most affordable flight options available to Boulder. Find the lowest fares based on data from user searches, with prices last updated on 29 October 2025.

Fri 31/1014:15SYD - DEN

2 stops27h 42mMultiple Airlines

Sun 16/1108:00DEN - SYD

2 stops43h 50mMultiple Airlines

Deal found 28/10$1,634

Sun 9/1113:55SYD - DEN

2 stops26h 00mAir New Zealand

Wed 12/1115:59DEN - SYD

2 stops22h 46mAir New Zealand

Deal found 26/10$1,762

Thu 11/1211:20SYD - DEN

1 stop22h 34mAmerican Airlines

Tue 30/1212:32DEN - SYD

2 stops26h 28mAmerican Airlines

Deal found 27/10$1,900

Fri 31/1011:20SYD - DEN

2 stops23h 34mBritish Airways

Sun 16/1119:17DEN - SYD

1 stop19h 43mBritish Airways

Deal found 28/10$1,926

Sun 9/1121:40SYD - DEN

2 stops30h 38mMultiple Airlines

Wed 12/1112:55DEN - SYD

1 stop24h 30mMultiple Airlines

Deal found 26/10$1,970

Sun 14/1214:50SYD - DEN

2 stops27h 27mMultiple Airlines

Tue 30/1206:00DEN - SYD

2 stops36h 30mMultiple Airlines

Deal found 27/10$2,130

Fri 12/1221:40SYD - DEN

2 stops35h 06mAlaska Airlines

Tue 30/1206:02DEN - SYD

2 stops43h 43mAlaska Airlines

Deal found 27/10$2,355

Sat 13/1221:40SYD - DEN

2 stops32h 21mAlaska Airlines

Tue 30/1206:02DEN - SYD

2 stops43h 43mAlaska Airlines

Deal found 27/10$2,415

Thu 11/1221:40SYD - DEN

2 stops32h 21mAlaska Airlines

Thu 18/1211:31DEN - SYD

2 stops38h 14mAlaska Airlines

Deal found 26/10$2,419

Wed 17/1211:20SYD - DEN

1 stop19h 03mQantas Airways

Sun 4/117:05DEN - SYD

1 stop21h 55mQantas Airways

Deal found 28/10$2,430

Best flights to Boulder
Discover carefully curated flight deals to Boulder that have cost, travel time, and stopovers in mind to ensure you get the best travel experience. Data last updated 29 October 2025.

Sat 7/211:45SYD - DEN

2 stops22h 47mAir New Zealand

Sat 21/213:45DEN - SYD

2 stops26h 45mAir New Zealand

Deal found 26/10$1,550

Thu 22/121:40SYD - DEN

2 stops31h 13mAlaska Airlines

Tue 10/319:50DEN - SYD

2 stops30h 55mAlaska Airlines

Deal found 27/10$1,819

Tue 20/109:00SYD - DEN

2 stops21h 37mAir Canada

Tue 10/319:05DEN - SYD

1 stop20h 30mAir Canada

Deal found 27/10$1,861

Tue 20/121:40SYD - DEN

2 stops32h 58mAlaska Airlines

Thu 12/319:50DEN - SYD

2 stops30h 55mAlaska Airlines

Deal found 27/10$1,822

Fri 13/211:20SYD - DEN

1 stop19h 08mAir Canada

Sun 22/217:30DEN - SYD

2 stops46h 05mAir Canada

Deal found 27/10$1,871

Fri 23/121:40SYD - DEN

2 stops32h 58mAlaska Airlines

Sun 8/319:50DEN - SYD

2 stops30h 55mAlaska Airlines

Deal found 27/10$1,822

Fri 23/121:40SYD - DEN

2 stops32h 58mAlaska Airlines

Thu 12/319:50DEN - SYD

2 stops30h 55mAlaska Airlines

Deal found 27/10$1,822

Thu 22/121:40SYD - DEN

2 stops31h 13mAlaska Airlines

Sun 8/319:50DEN - SYD

2 stops30h 55mAlaska Airlines

Deal found 27/10$1,822

Tue 20/121:40SYD - DEN

2 stops32h 58mAlaska Airlines

Fri 13/311:30DEN - SYD

2 stops39h 15mAlaska Airlines

Deal found 27/10$1,838

Thu 22/121:40SYD - DEN

2 stops31h 13mAlaska Airlines

Mon 9/312:30DEN - SYD

2 stops62h 15mAlaska Airlines

Deal found 27/10$1,859

Mon 19/121:40SYD - DEN

2 stops31h 58mAlaska Airlines

Wed 11/319:50DEN - SYD

2 stops30h 55mAlaska Airlines

Deal found 27/10$1,865

Mon 19/121:40SYD - DEN

2 stops31h 58mAlaska Airlines

Sun 8/319:50DEN - SYD

2 stops30h 55mAlaska Airlines

Deal found 27/10$1,865

Last-minute flights to Boulder
Discover last-minute flight deals to Boulder. Data last updated 29 October 2025 and is based on user searches.

Fri 31/1014:15SYD - DEN

2 stops27h 42mMultiple Airlines

Sun 16/1108:00DEN - SYD

2 stops43h 50mMultiple Airlines

Deal found 28/10$1,634

Fri 31/1011:20SYD - DEN

2 stops23h 34mBritish Airways

Sun 16/1119:17DEN - SYD

1 stop19h 43mBritish Airways

Deal found 28/10$1,926

Fri 31/1019:10SYD - DEN

3 stops39h 48mSingapore Airlines

Sun 16/1117:40DEN - SYD

2 stops33h 35mSingapore Airlines

Deal found 28/10$5,082

Sat 1/1121:40SYD - DEN

2 stops32h 47mAlaska Airlines

Sun 16/1118:46DEN - SYD

2 stops30h 59mAlaska Airlines

Deal found 27/10$7,716

Sat 1/1110:20SYD - DEN

1 stop19h 17mMultiple Airlines

Sun 16/1108:45DEN - SYD

2 stops29h 50mMultiple Airlines

Deal found 27/10$13,838

Sun 9/1113:55SYD - DEN

2 stops26h 00mAir New Zealand

Wed 12/1115:59DEN - SYD

2 stops22h 46mAir New Zealand

Deal found 26/10$1,762

Sun 9/1121:40SYD - DEN

2 stops30h 38mMultiple Airlines

Wed 12/1112:55DEN - SYD

1 stop24h 30mMultiple Airlines

Deal found 26/10$1,970

Sun 9/1119:10SYD - DEN

3 stops39h 16mSingapore Airlines

Wed 12/1108:03DEN - SYD

2 stops39h 52mSingapore Airlines

Deal found 26/10$4,584

Fri 28/1109:15SYD - DEN

2 stops27h 28mJapan Airlines

Mon 1/1219:17DEN - SYD

2 stops41h 33mJapan Airlines

Deal found 28/10$7,808

Fri 28/1109:00SYD - DEN

2 stops21h 37mAir Canada

Mon 1/1219:05DEN - SYD

1 stop20h 30mAir Canada

Deal found 28/10$12,840

One-way flights to Boulder
Search for one-way flight options to Boulder. Find affordable one-way fares based on user searches. Data last updated 29 October 2025.

Sun 15/214:00SYD - DEN

2 stops27h 10mMultiple Airlines

Deal found 28/10$819

Fri 13/311:45SYD - DEN

2 stops23h 12mAir New Zealand

Deal found 28/10$917

Thu 12/221:40SYD - DEN

3 stops45h 11mMultiple Airlines

Deal found 28/10$950

Sat 6/1221:40SYD - DEN

2 stops36h 59mMultiple Airlines

Deal found 28/10$959

Fri 13/221:40SYD - DEN

2 stops45h 21mMultiple Airlines

Deal found 28/10$965

Tue 17/221:40SYD - DEN

3 stops54h 12mMultiple Airlines

Deal found 28/10$967

Thu 12/313:55SYD - DEN

2 stops27h 27mAir New Zealand

Deal found 28/10$996

Sat 14/206:00SYD - DEN

2 stops37h 01mMultiple Airlines

Deal found 28/10$1,005

Fly from

Route

Depart

Return

Price

SydneyDenver

SYD - DEN

SYDDEN

Sydney Kingsford Smith

Sat 7/2

11:45-16:32

2 stops22h 47m

Denver Intl

Sat 21/2

13:45-10:30

2 stops26h 45m

$1,550

SydneyDenver

SYD - DEN

SYDDEN

Sydney Kingsford Smith

Thu 22/1

21:40-10:53

2 stops31h 13m

Denver Intl

Tue 10/3

19:50-19:45

2 stops30h 55m

$1,819

SydneyDenver

SYD - DEN

SYDDEN

Sydney Kingsford Smith

Tue 20/1

21:40-12:38

2 stops32h 58m

Denver Intl

Thu 12/3

19:50-19:45

2 stops30h 55m

$1,822

SydneyDenver

SYD - DEN

SYDDEN

Sydney Kingsford Smith

Fri 23/1

21:40-12:38

2 stops32h 58m

Denver Intl

Sun 8/3

19:50-19:45

2 stops30h 55m

$1,822

SydneyDenver

SYD - DEN

SYDDEN

Sydney Kingsford Smith

Fri 23/1

21:40-12:38

2 stops32h 58m

Denver Intl

Thu 12/3

19:50-19:45

2 stops30h 55m

$1,822

SydneyDenver

SYD - DEN

SYDDEN

Sydney Kingsford Smith

Thu 22/1

21:40-10:53

2 stops31h 13m

Denver Intl

Sun 8/3

19:50-19:45

2 stops30h 55m

$1,822

SydneyDenver

SYD - DEN

SYDDEN

Sydney Kingsford Smith

Tue 20/1

21:40-12:38

2 stops32h 58m

Denver Intl

Fri 13/3

11:30-19:45

2 stops39h 15m

$1,838

SydneyDenver

SYD - DEN

SYDDEN

Sydney Kingsford Smith

Thu 22/1

21:40-10:53

2 stops31h 13m

Denver Intl

Mon 9/3

12:30-19:45

2 stops62h 15m

$1,859

SydneyDenver

SYD - DEN

SYDDEN

Sydney Kingsford Smith

Tue 20/1

09:00-12:37

2 stops21h 37m

Denver Intl

Tue 10/3

19:05-08:35

1 stop20h 30m

$1,861

SydneyDenver

SYD - DEN

SYDDEN

Sydney Kingsford Smith

Mon 19/1

21:40-11:38

2 stops31h 58m

Denver Intl

Wed 11/3

19:50-19:45

2 stops30h 55m

$1,865

Flights are sorted by cheapest return flights first.

Deals found on 28/10

Showing 1-10 of 23 results

Best time to book a flight to Boulder

Have a flexible travel schedule? Discover the best time to fly to Boulder with our price prediction graph.

Estimated return 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 to Boulder

When is the best time to book a flight to Boulder?

The price you pay for your flight to Boulder may vary depending on when you book. For the best chance of a lower fare, look to book 46 days in advance of your trip. Fares are likely to increase a fortnight or so before your departure date.

How long is the flight to Boulder?

On average, a flight from Sydney to Boulder takes 20 hours 51 minutes. Flights to Boulder from other popular cities in Australia will vary in length. Below are a few examples of popular routes and their flight times.

What are the most popular airlines that fly to Boulder?

The most popular airlines flying from Sydney to Boulder are Qantas Airways, Air Canada and United Airlines.

What are the cheapest airlines that fly to Boulder?

The cheapest airlines flying from Sydney to Boulder are Qantas Airways, Air Canada and Air New Zealand.

Rainfall in Boulder by month

In terms of precipitation, rainfall in Boulder ranges from 13.0 - 58.0 mm per month. May is typically the wettest month, when rainfall can reach 58.0 mm. January is typically the driest time to visit Boulder when rainfall is around 13.0 mm.

Temperature in Boulder by month

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 23.0 C. Travellers hoping to avoid the cold should look outside of January, when temperatures are typically at their lowest (around -1.0 C).

Reviews of airlines servicing Boulder

See what other customers who have flown with Air New Zealand, Virgin Australia, andQantas Airways to the United States have to say. You can also see how each airline compares in terms of entertainment options, comfort, food, crew/service, and boarding process.

Air New Zealand

8.0

Very Good

520 reviews

Check prices

Reviews

1 / 20

6.0

Good

Anonymous,July 2025

AKL - SFO

Flight was delayed an hour. We had just flown Air NZ on a 12- hour flight from AKL so the extra delay on this connecting flight wasn’t welcomed.

Air New Zealand

8.0

Very Good

520 reviews

Air New Zealand

8.0

Very Good

520 reviews

Check prices

Reviews

1 / 20

6.0

Good

Anonymous,July 2025

AKL - SFO

Flight was delayed an hour. We had just flown Air NZ on a 12- hour flight from AKL so the extra delay on this connecting flight wasn’t welcomed.

Virgin Australia

7.6

Good

421 reviews

Air New Zealand

8.0

Very Good

520 reviews

Check prices

Reviews

1 / 20

6.0

Good

Anonymous,July 2025

AKL - SFO

Flight was delayed an hour. We had just flown Air NZ on a 12- hour flight from AKL so the extra delay on this connecting flight wasn’t welcomed.

Qantas Airways

7.5

Good

924 reviews

Air New Zealand

8.0

Very Good

520 reviews

Check prices

Reviews

1 / 20

6.0

Good

Anonymous,July 2025

AKL - SFO

Flight was delayed an hour. We had just flown Air NZ on a 12- hour flight from AKL so the extra delay on this connecting flight wasn’t welcomed.

United Airlines

7.4

Good

9,001 reviews

Air New Zealand

8.0

Very Good

520 reviews

Check prices

Reviews

1 / 20

6.0

Good

Anonymous,July 2025

AKL - SFO

Flight was delayed an hour. We had just flown Air NZ on a 12- hour flight from AKL so the extra delay on this connecting flight wasn’t welcomed.

Air Canada

7.1

Good

10,371 reviews

Air New Zealand

8.0

Very Good

520 reviews

Check prices

Reviews

1 / 20

6.0

Good

Anonymous,July 2025

AKL - SFO

Flight was delayed an hour. We had just flown Air NZ on a 12- hour flight from AKL so the extra delay on this connecting flight wasn’t welcomed.

FAQs about flying to Boulder

Can I find cheaper flights to Boulder if I am willing to have stopovers?
Yes, flights with stopovers are often cheaper than direct flights. Keep an eye out for flight deals to Boulder on Cheapflights that require 1 or 2 stops for potential cost savings.
What is the best airline to fly to Boulder?
Based on reviews from Cheapflights users, Qantas Airways is rated the highest out of the airlines that fly to Boulder.
How much is a return flight to Boulder?
A return flight to Boulder will typically cost around $107, however they can be found for as little as $106.
Where does the fastest flight to Boulder depart from?
For those looking to save time traveling to Boulder, Sydney Kingsford Smith offers the quickest one-way flight (20 hours 51 minutes).
Does Denver Intl have car hire?
Yes. Those touching down at Denver Intl can take advantage of the car hire services offered upon their arrival.
Are there hotels close to Denver Intl?
Yes. Denver Intl has hotels nearby for those requiring accommodations. The Westin Denver International Airport is the closest property to Denver Intl (0.0 km away from Denver Intl).

See more FAQs

Browse thousands of different options on Cheapflights for your next trip

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Fly with Cheapflights

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When you search for this flight to Boulder, Cheapflights searches on 900+ travel sites to save you time finding great flight deals online. Additionally, we offer filter features so you can choose a preferred cabin class or airline, see different price ranges, and much more so you can book the best flight for you.

Why should you use Cheapflights to find cheap flight tickets to Boulder?

Cheapflights helps you find that perfect flight to Boulder by searching from hundreds of airlines and agencies you know and love. We are also free to use, in case you were wondering!

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Users can book flights with no change fees policies with our dedicated filters. Book flights to Boulder flexibly with Cheapflights today.

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$819+ Cheap flights to Boulder

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 15/2. Fares are subject to change and may not be available on all flights or dates of travel.

Flights to Boulder in 2025

Find the latest flights to Boulder in 2025, with up-to-date prices and availability. In the last 7 days, Cheapflights users made a total of 647,157 searches and data was last updated on 29 October 2025.

Return from

One-way from

Popular in

Cheapest in

Average price

Find flight deals to Boulder

Cheapest flights to BoulderExplore the most affordable flight options available to Boulder. Find the lowest fares based on data from user searches, with prices last updated on 29 October 2025.

Explore the most affordable flight options available to Boulder. Find the lowest fares based on data from user searches, with prices last updated on 29 October 2025.

Cheapflights Fare Finder

Use the filters below to find and compare flights to Boulder that are best for you.

Best time to book a flight to Boulder

Have a flexible travel schedule? Discover the best time to fly to Boulder with our price prediction graph.

Cheapflights Insights

Everything you need to know about your flight to Boulder

When is the best time to book a flight to Boulder?

Use this chart to determine the optimal time to book a return flight from Sydney to Boulder. Price data was last updated on 24 October 2025.

How long is the flight to Boulder?

What are the most popular airlines that fly to Boulder?

What are the cheapest airlines that fly to Boulder?

Rainfall in Boulder by month

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

Temperature in Boulder by month

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

Reviews of airlines servicing Boulder

See what other customers who have flown with Air New Zealand, Virgin Australia, andQantas Airways to the United States have to say. You can also see how each airline compares in terms of entertainment options, comfort, food, crew/service, and boarding process.

FAQs about flying to Boulder

Can I find cheaper flights to Boulder if I am willing to have stopovers?

What is the best airline to fly to Boulder?

How much is a return flight to Boulder?

Where does the fastest flight to Boulder depart from?

Does Denver Intl have car hire?

Are there hotels close to Denver Intl?

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.

Search flights to Boulder by cabin class

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

Fly with Cheapflights

Find the best flight deals on Cheapflights, where travellers can enjoy low prices and a wide availability of flights to their desired destinations.

How does Cheapflights help users find flights to Boulder?

Why should you use Cheapflights to find cheap flight tickets to Boulder?

Can Cheapflights find flights to Boulder with no change fees?

Can Cheapflights notify me if prices for flights to Boulder become cheaper?

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Cheapest flights to Boulder
Explore the most affordable flight options available to Boulder. Find the lowest fares based on data from user searches, with prices last updated on 29 October 2025.