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C$ 177+ 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 20/10. Fares are subject to change and may not be available on all flights or dates of travel.
— DEN
11 Oct — 18 Oct1
1 adult
1 adult, Economy

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 11 September 2025.

Round-trip from

C$ 427

One-way from

C$ 177

Popular in

December

Cheapest in

August

Average price

C$ 588
30/10-1/11
  • 30/10-1/11
  • 4 total stops
  • 37h 34m total
  • Toronto to Denver
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20/10
  • 20/10
  • 2 total stops
  • 24h 21m total
  • Toronto to Boulder
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Highest demand for flights based on searches. 4% potential increase in price (C$ 38 potential increase over avg. RT price).
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Cheapest flight prices on average. 1% potential price decrease (C$ 10 potential savings vs. average RT price).
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Average for round-trip flights in September 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 11 September 2025.

Thu 30/101:30 p.m.YYZ - DEN
3 stops24h 30mMultiple Airlines
Sat 1/1112:16 a.m.DEN - YYZ
1 stop13h 04mMultiple Airlines
Deal found 10/9C$ 427
Sun 21/94:00 p.m.YYZ - DEN
1 stop18h 16mMultiple Airlines
Fri 3/1012:15 p.m.DEN - YYZ
1 stop10h 07mMultiple Airlines
Deal found 9/9C$ 428
Mon 15/92:00 p.m.YYZ - DEN
2 stops16h 00mMultiple Airlines
Fri 3/1012:15 p.m.DEN - YYZ
1 stop10h 07mMultiple Airlines
Deal found 9/9C$ 430
Wed 5/116:00 a.m.YYZ - DEN
1 stop18h 22mAmerican Airlines
Tue 11/117:22 a.m.DEN - YYZ
1 stop12h 07mAmerican Airlines
Deal found 9/9C$ 431
Sun 21/910:25 p.m.YYZ - DEN
2 stops38h 31mMultiple Airlines
Wed 15/1010:29 p.m.DEN - YYZ
1 stop19h 16mMultiple Airlines
Deal found 9/9C$ 432
Fri 26/97:45 p.m.YYZ - DEN
1 stop16h 33mMultiple Airlines
Sun 5/1012:04 a.m.DEN - YYZ
2 stops19h 03mMultiple Airlines
Deal found 9/9C$ 434
Sat 18/104:00 p.m.YYZ - DEN
1 stop18h 12mMultiple Airlines
Wed 22/108:21 p.m.DEN - YYZ
1 stop22h 46mMultiple Airlines
Deal found 9/9C$ 435
Sun 12/1010:25 p.m.YYZ - DEN
1 stop14h 59mMultiple Airlines
Fri 17/1011:59 p.m.DEN - YYZ
1 stop12h 26mMultiple Airlines
Deal found 10/9C$ 437
Fri 3/108:00 a.m.YYZ - DEN
1 stop11h 18mAir Canada
Sat 11/108:40 a.m.DEN - YYZ
1 stop9h 12mAir Canada
Deal found 9/9C$ 438
Sat 1/1112:40 p.m.YYZ - DEN
1 stop9h 25mMultiple Airlines
Thu 13/117:00 a.m.DEN - YYZ
1 stop11h 32mMultiple Airlines
Deal found 9/9C$ 439
Fri 26/97:15 a.m.YYZ - DEN
2 stops16h 16mMultiple Airlines
Sun 5/103:43 p.m.DEN - YYZ
1 stop13h 16mMultiple Airlines
Deal found 10/9C$ 441
Tue 28/109:35 a.m.YYZ - DEN
1 stop12h 30mMultiple Airlines
Fri 31/109:05 a.m.DEN - YYZ
1 stop8h 55mMultiple Airlines
Deal found 10/9C$ 442

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 11 September 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

YTZ - DEN

YTZDEN

Toronto Island

Mon 20/10

8:45 a.m.-8:30 p.m.

1 stop13h 45m

Denver Intl

Wed 29/10

7:40 a.m.-8:00 p.m.

1 stop10h 20m

C$ 453

TorontoDenver

YTZ - DEN

YTZDEN

Toronto Island

Wed 5/11

12:30 p.m.-7:55 p.m.

1 stop9h 25m

Denver Intl

Tue 11/11

11:15 a.m.-9:35 p.m.

1 stop8h 20m

C$ 455

TorontoDenver

YTZ - DEN

YTZDEN

Toronto Island

Fri 17/10

1:35 p.m.-8:30 p.m.

1 stop8h 55m

Denver Intl

Mon 20/10

6:38 a.m.-5:53 p.m.

1 stop9h 15m

C$ 456

TorontoDenver

YTZ - DEN

YTZDEN

Toronto Island

Mon 13/10

9:45 a.m.-11:16 p.m.

2 stops15h 31m

Denver Intl

Mon 20/10

9:26 p.m.-12:17 p.m.

1 stop12h 51m

C$ 461

TorontoDenver

YYZ - DEN

YYZDEN

Toronto Pearson Intl

Fri 24/10

8:05 p.m.-3:59 a.m.

1 stop9h 54m

Denver Intl

Tue 28/10

10:29 p.m.-7:36 p.m.

2 stops19h 07m

C$ 466

TorontoDenver

YTZ - DEN

YTZDEN

Toronto Island

Sun 12/10

3:00 p.m.-1:08 a.m.

1 stop12h 08m

Denver Intl

Fri 17/10

9:19 p.m.-12:17 p.m.

1 stop12h 58m

C$ 473

TorontoDenver

YYZ - DEN

YYZDEN

Toronto Pearson Intl

Fri 3/10

6:13 p.m.-9:25 p.m.

1 stop5h 12m

Denver Intl

Fri 10/10

12:55 a.m.-11:20 a.m.

1 stop8h 25m

C$ 484

TorontoDenver

YYZ - DEN

YYZDEN

Toronto Pearson Intl

Fri 24/10

3:35 p.m.-10:06 p.m.

1 stop8h 31m

Denver Intl

Sun 26/10

12:50 a.m.-12:10 p.m.

1 stop9h 20m

C$ 484

TorontoDenver

YTZ - DEN

YTZDEN

Toronto Island

Sat 1/11

7:45 a.m.-7:59 p.m.

2 stops14h 14m

Denver Intl

Mon 3/11

8:44 p.m.-1:42 p.m.

1 stop14h 58m

C$ 489

TorontoDenver

YTZ - DEN

YTZDEN

Toronto Island

Fri 24/10

7:50 a.m.-1:57 p.m.

1 stop8h 07m

Denver Intl

Thu 30/10

12:59 a.m.-6:55 p.m.

2 stops15h 56m

C$ 491

Flights are sorted by cheapest round-trip flights first.

Deals found on 9/9

Showing 1-10 of 60 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 29 August 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 9 hours 39 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 (11 on average). You will have fewer flight options on Wednesday, which is when the least amount of flights are scheduled (10 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$ 64
United Airlines
United Airlines
From C$ 143
WestJet
WestJet
From C$ 122
Delta
Delta
From C$ 154

What are the cheapest airlines that fly to Boulder?

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

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 11 September 2025.
Check out reviews from past customers who have flown United Airlines,WestJet, andAir Canada to the United States to help guide your decision. You can also see how each airline stacks up in terms of entertainment options, comfort, food, crew/service, and boarding process.
United Airlines
7.4
Good
8,937 reviews
Check prices

Crew

8.1

Boarding

7.7

Entertainment

7.1

Overall

7.4

Food

6.6

Comfort

7.3

Reviews

1 / 20
8.0
Excellent

Anonymous,Dec 2024

YVR - SFO

It was a good experience. The flight took 45 minutes longer to fly and all passengers had to wait inside the plane till the technical issue was fixed. Overall it was a good experience.
United Airlines
7.4
Good
8,937 reviews
United Airlines
7.4
Good
8,937 reviews
Check prices

Crew

8.1

Boarding

7.7

Entertainment

7.1

Overall

7.4

Food

6.6

Comfort

7.3

Reviews

1 / 20
8.0
Excellent

Anonymous,Dec 2024

YVR - SFO

It was a good experience. The flight took 45 minutes longer to fly and all passengers had to wait inside the plane till the technical issue was fixed. Overall it was a good experience.
WestJet
7.2
Good
3,091 reviews
United Airlines
7.4
Good
8,937 reviews
Check prices

Crew

8.1

Boarding

7.7

Entertainment

7.1

Overall

7.4

Food

6.6

Comfort

7.3

Reviews

1 / 20
8.0
Excellent

Anonymous,Dec 2024

YVR - SFO

It was a good experience. The flight took 45 minutes longer to fly and all passengers had to wait inside the plane till the technical issue was fixed. Overall it was a good experience.
Air Canada
7.1
Good
10,000 reviews
United Airlines
7.4
Good
8,937 reviews
Check prices

Crew

8.1

Boarding

7.7

Entertainment

7.1

Overall

7.4

Food

6.6

Comfort

7.3

Reviews

1 / 20
8.0
Excellent

Anonymous,Dec 2024

YVR - SFO

It was a good experience. The flight took 45 minutes longer to fly and all passengers had to wait inside the plane till the technical issue was fixed. Overall it was a good experience.

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$ 447, 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 13 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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