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C$ 271+ 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 17/6. Fares are subject to change and may not be available on all flights or dates of travel.
— DEN
17 Jun — 24 Jun1
1 adult

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 629,999 searches and data was last updated on 12 June 2025.

Round-trip from

C$ 375

One-way from

C$ 271

Popular in

December

Cheapest in

September

Average price

C$ 602
WestJet
  • WestJet
  • 8/8-11/8
  • 3 total stops
  • 27h 06m total
  • Toronto to Denver
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Delta
  • Delta
  • 17/6
  • 1 total stop
  • 6h 35m total
  • Toronto to Boulder
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Highest demand for flights based on searches. 3% potential increase in price (C$ 34 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 1% potential price decrease (C$ 12 potential savings vs. average RT price).
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Average for round-trip flights in June 2025
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Find flight deals to Boulder

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 12 June 2025.

Fri 8/87:00 p.m.YYZ - DEN
2 stops18h 27mWestJet
Mon 11/812:15 p.m.DEN - YYZ
1 stop8h 39mWestJet
Deal found 9/6C$ 375
Fri 1/810:00 a.m.YYZ - DEN
2 stops15h 21mMultiple Airlines
Sun 3/812:15 p.m.DEN - YYZ
1 stop10h 09mMultiple Airlines
Deal found 12/6C$ 414
Thu 4/97:45 p.m.YKF - DEN
1 stop17h 39mWestJet
Mon 8/912:15 p.m.DEN - YKF
1 stop28h 40mWestJet
Deal found 10/6C$ 417
Wed 18/68:40 a.m.YYZ - DEN
Nonstop3h 40mAir Canada
Sat 21/67:45 a.m.DEN - YYZ
Nonstop3h 13mAir Canada
Deal found 11/6C$ 428
Fri 13/61:25 p.m.YYZ - DEN
1 stop10h 53mAmerican Airlines
Tue 17/67:00 a.m.DEN - YYZ
1 stop5h 55mAmerican Airlines
Deal found 10/6C$ 462
Fri 13/62:27 p.m.YYZ - DEN
1 stop8h 08mDelta
Tue 17/612:55 a.m.DEN - YYZ
1 stop6h 26mDelta
Deal found 10/6C$ 463
Tue 15/712:25 p.m.YTZ - DEN
1 stop7h 55mAir Canada
Fri 18/79:40 a.m.DEN - YTZ
1 stop8h 06mAir Canada
Deal found 10/6C$ 465
Mon 4/86:00 a.m.YKF - DEN
1 stop31h 27mMultiple Airlines
Mon 6/1012:15 p.m.DEN - YKF
1 stop15h 00mMultiple Airlines
Deal found 10/6C$ 472
Fri 13/65:15 p.m.YYZ - DEN
1 stop7h 03mBritish Airways
Sat 21/67:20 a.m.DEN - YYZ
1 stop13h 30mBritish Airways
Deal found 10/6C$ 472
Wed 9/78:55 p.m.YHM - DEN
1 stop16h 32mMultiple Airlines
Wed 16/712:15 p.m.DEN - YHM
1 stop10h 26mMultiple Airlines
Deal found 10/6C$ 526
Fri 8/84:05 p.m.YTZ - DEN
2 stops21h 22mMultiple Airlines
Mon 11/812:15 p.m.DEN - YTZ
2 stops19h 22mMultiple Airlines
Deal found 9/6C$ 551
Fri 15/86:00 a.m.YHM - DEN
2 stops41h 44mWestJet
Sat 23/812:15 p.m.DEN - YHM
1 stop10h 26mWestJet
Deal found 11/6C$ 755

Cheapflights Fare Finder

Locate flights to Boulder that fit your budget, with regularly updated fares and availability. In the last 7 days, Cheapflights users made a total of 629,999 searches and data was last updated on 12 June 2025.
Use the filters below to find and compare flights to Boulder that are best for you.

Fly from

Toronto

Route

Depart

Return

Price

TorontoDenver

YYZ - DEN

YYZDEN

Toronto Pearson Intl

Fri 8/8

7:00 p.m.-11:27 a.m.

2 stops18h 27m

Denver Intl

Mon 11/8

12:15 p.m.-10:54 p.m.

1 stop8h 39m

C$ 375

TorontoDenver

YYZ - DEN

YYZDEN

Toronto Pearson Intl

Fri 1/8

10:00 a.m.-11:21 p.m.

2 stops15h 21m

Denver Intl

Sun 3/8

12:15 p.m.-12:24 a.m.

1 stop10h 09m

C$ 414

TorontoDenver

YKF - DEN

YKFDEN

Toronto Region of Waterloo Intl

Thu 4/9

7:45 p.m.-11:24 a.m.

1 stop17h 39m

Denver Intl

Mon 8/9

12:15 p.m.-6:55 p.m.

1 stop28h 40m

C$ 417

TorontoDenver

YYZ - DEN

YYZDEN

Toronto Pearson Intl

Wed 16/7

8:40 a.m.-10:20 a.m.

Nonstop3h 40m

Denver Intl

Tue 22/7

7:45 a.m.-12:58 p.m.

Nonstop3h 13m

C$ 438

TorontoDenver

YTZ - DEN

YTZDEN

Toronto Island

Tue 15/7

12:25 p.m.-6:20 p.m.

1 stop7h 55m

Denver Intl

Fri 18/7

9:40 a.m.-7:46 p.m.

1 stop8h 06m

C$ 465

TorontoDenver

YKF - DEN

YKFDEN

Toronto Region of Waterloo Intl

Mon 4/8

6:00 a.m.-11:27 a.m.

1 stop31h 27m

Denver Intl

Mon 6/10

12:15 p.m.-5:15 a.m.

1 stop15h 00m

C$ 472

TorontoDenver

YYZ - DEN

YYZDEN

Toronto Pearson Intl

Fri 11/7

5:45 p.m.-10:11 p.m.

1 stop6h 26m

Denver Intl

Thu 17/7

12:59 a.m.-10:19 a.m.

1 stop7h 20m

C$ 494

TorontoDenver

YYZ - DEN

YYZDEN

Toronto Pearson Intl

Thu 3/7

6:00 a.m.-3:05 p.m.

1 stop11h 05m

Denver Intl

Mon 7/7

5:32 p.m.-10:59 a.m.

1 stop15h 27m

C$ 495

HamiltonDenver

YHM - DEN

YHMDEN

Hamilton

Wed 9/7

8:55 p.m.-11:27 a.m.

1 stop16h 32m

Denver Intl

Wed 16/7

12:15 p.m.-12:41 a.m.

1 stop10h 26m

C$ 526

TorontoDenver

YTZ - DEN

YTZDEN

Toronto Island

Fri 8/8

4:05 p.m.-11:27 a.m.

2 stops21h 22m

Denver Intl

Mon 11/8

12:15 p.m.-9:37 a.m.

2 stops19h 22m

C$ 551

Flights are sorted by cheapest round-trip flights first.

Deals found on 11/6

Showing 1-10 of 25 results
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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 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 to Boulder

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

Use this chart to determine the optimal time to book a round-trip flight from Toronto to Boulder. Price data was last updated on 9 June 2025.

Booking 85 days in advance of your planned departure date is, on average, the best time to get cheap flights to Boulder. The general trend is that the closer you book to the departure date, the more expensive your flight will be.

How long is the flight to Boulder?

On average, a flight from Toronto to Boulder takes 10 hours 8 minutes. Flights to Boulder from other popular cities in Canada will vary in length. Below are a few examples of popular routes and their flight times.

Weekly flight availability to Boulder

The most flights from Toronto to Boulder are scheduled on a Monday (10 on average). You will have fewer flight options on Friday, which is when the least amount of flights are scheduled (7 on average).

What are the most popular airlines that fly to Boulder?

The most popular airlines flying from Toronto to Boulder are Air Canada, United Airlines and WestJet.

Air Canada
Air Canada
From C$ 349
United Airlines
United Airlines
From C$ 376
WestJet
WestJet
From C$ 188
Frontier
Frontier
From C$ 153

What are the cheapest airlines that fly to Boulder?

The cheapest airlines flying from Toronto to Boulder are Frontier, WestJet and Air Canada.

Rainfall in Boulder by month

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

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

Get insights into the airlines that provide service to Boulder. 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 Boulder. Reviews last updated 12 June 2025.
To help decide which airline to fly to Boulder, see what other customers have to say about Alaska Airlines, Delta and United Airlines. 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
10,000 reviews
Check prices

Crew

8.5

Overall

8.0

Food

7.1

Comfort

7.8

Entertainment

7.1

Boarding

8.1

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
10,000 reviews
Alaska Airlines
8.0
Very good
10,000 reviews
Check prices

Crew

8.5

Overall

8.0

Food

7.1

Comfort

7.8

Entertainment

7.1

Boarding

8.1

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
7,946 reviews
Alaska Airlines
8.0
Very good
10,000 reviews
Check prices

Crew

8.5

Overall

8.0

Food

7.1

Comfort

7.8

Entertainment

7.1

Boarding

8.1

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
8,790 reviews
Alaska Airlines
8.0
Very good
10,000 reviews
Check prices

Crew

8.5

Overall

8.0

Food

7.1

Comfort

7.8

Entertainment

7.1

Boarding

8.1

Reviews

1 / 20
10.0
Excellent

James,Apr 2025

LAX - SFO

Good flight except the uncontrollable cold air from the ceiling.
American Airlines
7.2
Good
10,000 reviews
Alaska Airlines
8.0
Very good
10,000 reviews
Check prices

Crew

8.5

Overall

8.0

Food

7.1

Comfort

7.8

Entertainment

7.1

Boarding

8.1

Reviews

1 / 20
10.0
Excellent

James,Apr 2025

LAX - SFO

Good flight except the uncontrollable cold air from the ceiling.
WestJet
7.2
Good
2,868 reviews
Alaska Airlines
8.0
Very good
10,000 reviews
Check prices

Crew

8.5

Overall

8.0

Food

7.1

Comfort

7.8

Entertainment

7.1

Boarding

8.1

Reviews

1 / 20
10.0
Excellent

James,Apr 2025

LAX - SFO

Good flight except the uncontrollable cold air from the ceiling.

FAQs about flying to Boulder

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

    Yes, flights with layovers 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, WestJet is rated the highest out of the airlines that fly to Boulder.

  • How much is a round-trip flight to Boulder?

    A round-trip flight to Boulder will typically cost around C$ 388, however they can be found for as little as C$ 76.

  • Where does the fastest flight to Boulder depart from?

    For those looking to save time traveling to Boulder, Regina offers the quickest one-way flight (2 hours 15 minutes).

  • Does Denver Intl have rental cars?

    Yes. Those touching down at Denver Intl can take advantage of the rental car 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

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