$53 Find Cheap Flights from Phoenix to Boulder

This is the cheapest one-way flight price found by a KAYAK user in the last 72 hours by searching for a flight from Phoenix to Boulder departing on 5/1. Fares are subject to change and may not be available on all flights or dates of travel. Click the price to replicate the search for this deal.
1 adult
1 adult, Economy, 0 bags

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Everything you should know

Cheapest round-trip
$68
Overall average: $157
Frontier
ons 4/22mån 4/27
PHX - DEN • Non-stop
Cheapest one-way
$53
Typical prices: $92-$168
Frontier
fre 5/1
PHX - DEN • Non-stop
Arrival airport
You can't fly directly to Boulder. It is served by Denver (DEN), located 33.4 miles from Boulder.
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Flight Deals
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Flight Deals

Cheap Flights from Phoenix to Boulder (PHX-DEN)

 
Here are some of the best deals found on KAYAK recently from the most popular airlines for round-trip flights from Phoenix to Boulder that are departing in the next months. While these flights were available on KAYAK in the last 72 hours, prices and availability are subject to change and deals may expire.
Discover the best prices for you by selecting your travel dates on KAYAK.

Recent round-trip flight deals from Phoenix to Boulder

ons, apr 22 - mån, apr 27
Frontier Logo
6:51 pm - 9:44 pm
PHX
-
DEN
1h 53mnonstop
Frontier Logo
6:30 am - 7:36 am
DEN
-
PHX
2h 06mnonstop
$68Frontier
lör, apr 18 - mån, apr 20
Frontier Logo
9:24 pm - 12:20 am
PHX
-
DEN
1h 56mnonstop
Frontier Logo
7:11 pm - 8:16 pm
DEN
-
PHX
2h 05mnonstop
$71Frontier
lör, maj 2 - tors, maj 7
Frontier Logo
12:50 pm - 3:45 pm
PHX
-
DEN
1h 55mnonstop
Frontier Logo
6:30 am - 7:36 am
DEN
-
PHX
2h 06mnonstop
$72Frontier
ons, apr 22 - mån, apr 27
Frontier Logo
12:50 pm - 3:45 pm
PHX
-
DEN
1h 55mnonstop
Frontier Logo
7:11 pm - 8:16 pm
DEN
-
PHX
2h 05mnonstop
$73Frontier
tors, maj 7 - sön, maj 10
Frontier Logo
6:45 pm - 9:38 pm
PHX
-
DEN
1h 53mnonstop
Frontier Logo
6:30 am - 7:36 am
DEN
-
PHX
2h 06mnonstop
$77Frontier
lör, apr 4 - lör, apr 11
Frontier Logo
6:52 pm - 9:45 pm
PHX
-
DEN
1h 53mnonstop
Frontier Logo
4:40 pm - 5:47 pm
DEN
-
PHX
2h 07mnonstop
$78Frontier
mån, apr 13 - mån, apr 20
Frontier Logo
9:24 pm - 12:20 am
PHX
-
DEN
1h 56mnonstop
Frontier Logo
7:11 pm - 8:16 pm
DEN
-
PHX
2h 05mnonstop
$79Frontier
tors, apr 16 - tis, apr 21
Frontier Logo
6:50 am - 9:43 am
PHX
-
DEN
1h 53mnonstop
Frontier Logo
10:35 pm - 11:42 pm
DEN
-
PHX
2h 07mnonstop
$81Frontier
fre, apr 3 - tis, apr 21
Frontier Logo
6:52 pm - 9:45 pm
PHX
-
DEN
1h 53mnonstop
Frontier Logo
10:35 pm - 11:42 pm
DEN
-
PHX
2h 07mnonstop
$82Frontier
lör, apr 25 - ons, apr 29
Frontier Logo
9:52 am - 12:55 pm
PHX
-
DEN
2h 03mnonstop
Frontier Logo
10:35 pm - 11:42 pm
DEN
-
PHX
2h 07mnonstop
$83Frontier
Useful Info

Good to know

Low seasonFebruary
Cheapest flight$53
Best time to beat the crowds with an average 15% drop in price.
Most popular time to fly with an average 6% increase in price.
Flight from Phoenix Sky Harbor Airport to Denver

When to book flights from Phoenix to Boulder

Are your dates flexible? Find out the best times to travel from Phoenix to Boulder based on our flight data from the last year. Discover the cheapest month and even day to fly.
Estimated round-trip price

FAQs for booking flights from Phoenix to Boulder

  • Which airports will I be using when flying from Phoenix Sky Harbor Intl Airport to Boulder?

    When flying out of Phoenix Sky Harbor Intl Airport you’ll be using Phoenix Sky Harbor Intl. Boulder does not have its own airport so you’ll be flying into nearby Denver Intl airport, which is 33.4 mi away.

  • How long does a flight from Phoenix Sky Harbor Intl Airport to Boulder take?

    Direct flights cover the 601 miles separating Phoenix Sky Harbor Intl Airport and Boulder in about 1h 45m.

  • How many flights are there between Phoenix Sky Harbor Intl Airport and Boulder?

    79 direct flights run between Phoenix Sky Harbor Intl Airport and Boulder on a daily basis. On average, there are about 557 departures each week.

  • What’s the cheapest day of the week to fly between Phoenix Sky Harbor Intl Airport and Boulder?

    Consider leaving on a Friday and avoid Saturdays if you are looking for the best rates. For your return to Phoenix Sky Harbor Intl Airport, you’ll find the best rates on Fridays and the most expensive ones on Thursdays.

  • How does KAYAK find such low prices on flights from Phoenix to Boulder?

    KAYAK is a travel search engine. That means we look across the web to find the best prices we can find for our users. With over 2 billion flight queries processed yearly, we are able to display a variety of prices and options on flights from Phoenix to Boulder.

  • How does KAYAK's flight Price Forecast tool help me choose the right time to buy my flight ticket from Phoenix to Boulder?

    KAYAK’s flight Price Forecast tool uses historical data to determine whether the price for a flight to Boulder from Phoenix is likely to change within 7 days, so travelers know whether to wait or book now.

  • What is the Hacker Fare option on flights from Phoenix to Boulder?

    Hacker Fares allow you to combine one-way tickets in order to save you money over a traditional round-trip ticket. You could then fly to Boulder with an airline and back to Phoenix with another airline.

  • What is KAYAK's "flexible dates" feature and why should I care when looking for a flight from Phoenix to Boulder?

    Sometimes travel dates aren't set in stone. If your preferred travel dates have some wiggle room, flexible dates will show you all the options when flying to Boulder from Phoenix up to 3 days before/after your preferred dates. You can then pick the flights that suit you best.

  • Which airlines provide the cheapest flights from Phoenix Sky Harbor Intl Airport to Boulder?

    In the last 72 hours, the cheapest one-way ticket between Phoenix Sky Harbor Intl Airport and Boulder found on KAYAK was with Frontier for $36. Frontier offered a round-trip connection from $63 and United Airlines from $135.

Top tips for finding cheap flights from Phoenix Sky Harbor Intl Airport to Boulder

  • There is no airport in Boulder. Instead, you’ll be flying into Denver Airport when flying between Phoenix Sky Harbor Intl Airport and Boulder.
  • The cheapest flight from Phoenix to Boulder was found 69 days before departure, on average.
  • Book at least 2 weeks before departure in order to get a below-average price.
  • High season is considered to be May, June and July. The cheapest month to fly is February.

Reviews of the top 4 airlines serving Phoenix to Boulder

 
Need help choosing which airline to fly with from Phoenix to Boulder? KAYAK airline reviews give an overall score for each airline based on loads of factors, including comfort, boarding, in-flight entertainment and more, to make your decision easier. See airline scores according to verified KAYAK customer reviews.
8.0
SouthwestOverall score based on 4318 reviews
7.0Food
7.5Entertainment
8.6Crew
8.1Boarding
8.0Comfort
Airline reviews

Mediocre. Boarding is now unpleasant. The employees, once friendly and nice, are now regularly speaking sternly to passengers, badgering them to do things right so they can take off on time and gate check bags because they don't have enough overhead bin space. The pretzel snack was crushed flat and broken into even smaller pieces, which happens frequently lately. Drink service was suspended before they reached my row.

4.0 OkayAnonymous, Mar 2026
PHX - LAX
Read more Southwest reviews

Mediocre. Boarding is now unpleasant. The employees, once friendly and nice, are now regularly speaking sternly to passengers, badgering them to do things right so they can take off on time and gate check bags because they don't have enough overhead bin space. The pretzel snack was crushed flat and broken into even smaller pieces, which happens frequently lately. Drink service was suspended before they reached my row.

I appreciate the staff who allowed me to board though I arrived a little late! Regarding the assigned seating, I had booked my flight before this change and wasn't aware of the change at the time, and so I didn't select a seat at booking as I didn't realize it was relevant. Better communication about the change would have been helpful for preparing.

WIFI was great. My selection for seating is an aisle, but during my trip, I never had an aisle seat. If we can get that corrected, I will be thrilled.

All good except once again bags took an hour at Midway Airport Happens all the time. Ridiculous

Sacrament staff are always polite and helpful. Airport is easy to maneuver and boarding is straightforward.

mandatory demand customer to check their carry on because not enough people check bags.

Near 4 hour flight with only 1 service. Had to use call button to request water. Internet and power not working until into flight. Internet would stop working during flight.

The Southwest employees (all two of them) were very nice and cheerful despite the fact the line to self-check a bag (simply drop it off) was hundreds of people long. Thank God I arrived early to the airport because I stood in this line for at least an hour. Once on the flight that had been delayed by an hour, we had no Wi-Fi and thus no entertainment. Finally, I hope the investor strong arm tactics against Southwest pay off in a short-term windfall to your C-Suite because the rest of you are screwed. I have been a faithful Southwest customer for 15 years due to everything you just got rid of. I'm flying to Idaho and Washington in October, both places I used to simply book with Southwest without a second thought now with Frontier (Washington) and United (Idaho) because they offer everything the "new" Southwest does but cheaper and at better times, destinations, etc. This really makes me sad...

First time traveling on Southwest since bag fees were implemented. Usual good service. Just more expensive now.

Flights delayed by 4-6 hours. Boarding was a mess and unclear. Bags were not at arrival airport and had never even been put on the plane. No idea when I’ll get them. Don’t fly into Denver!

Seats are uncomfortable. This has been a trend in the industry for decades. Trying to fit more seats on each plane to increase profits at the expense of the passenger.

It’s always a great time flying with united airlines.

We got delayed three hours and nobody thought to have the bathroom fixed while we were sitting waiting to board? took a full hour to have maintenance come and check it off. Had to shut the bathroom down twice so that the pilots could go to the bathroom. Everyone missed their connections.

Women boarding passengers at the gate was absolutely rude and disrespectful of passengers. The flight attendant was absolutely delightful! Smiling and connected with the passengers. So happy. The seats are cramped and uncomfortable but I guess that’s just the way it is Communication regarding flight was excellent

As great a red-eye flight as red-eye flights can be.

Both of my flights arrived early and check in process was smooth

Everything was on time Will use united again for sure

I upgraded my seat and was promised it would be next to the emergency door for extra leg room and they said it was premium plus but it was at the back of the plane...same thing happened from Newark to Dubai

Check-in, boarding and the flight from Phoenix to Houston was quick and easy. The flight from Houston to Shreveport was delayed 5 hours. It was frustrating but I think United handled it the best they could.

The flight was delayed by two de-icings. The seatbelt did not work correctly. It did not stay tight.

The baggage claim experience was poor. The plane crew and the AA app said that checked baggage in CLT would be at carousel 7 but the sign at Baggage Claim said carousel 1. The carousel 1 sign had the correct flight # listed above the belt. But the luggage never came. I went to an AA baggage claim office after about 1 hour and the clerk directed me to another AA room that was poorly marked, with a closed door and no obvious way to know what to do. Finally someone opened the door and my bag was inside. The clerk was totally unable to explain why.

Lack of gluten free options in food service. I have Celiac disease and it appears you no longer offer special meals for people with dietary restrictions. I am a frequent flyer traveling into and out of Omaha airport. I have noticed over the course of several months that although our flight typically arrives ahead of schedule (awesome job AA!) - we typically sit on the runway for several minutes waiting for the ground crew to get in place. Not sure if it is a ground crew issue or a gate availability issue (due to construction at this airport). Seems to be more of a ground crew being on time issue.

Arriving plane went to wrong gate. Flight Attendant was late. Was in no Hurry when he arrived. Flight was fine. Plane had to wait 20 minutes to get assigned a gate due to designated gate tied up. barely connected.. Boarded extremely late on final leg of trip.

one crew said "he" didn't serve double alcohol drinks for travelers in exit rows. crew on prior flight did. Is this a AA rule, and the prior crew was being nice? Also, I think we deserve more than a 25% refund for losing first class seats when rescheduling a flight due to weather

Amazing I love American. I’ll never fly anyone else if I can help it.

Experience was good. We were delayed in leaving by 15 mins because the flight was waiting on a family that was late in getting to the gate. Food and drink options were as expected. I highly recommend checking in ahead of time using the airline’s app so that it’s quicker to get your luggage tags as soon as you arrive at the terminal. No more waiting in long lines!

The captain brought my 6 year old son into the cockpit and allowed him to ask questions, sit in the captain’s chair and talk about all the gears and levers. Made the trip very special for him.

Better service. No food options, but we did get drinks and a cookie.

it was fine, decent flight... dont get food besides cookies or pretzels so not sure why you ask about food. same for entertainment..

Liked that it was on time. Staff professional and friendly.

Our flight was canceled. I will never use Kayak nor Frontier for travel again. The entire experience was a headache.

Good for a budget airline! It was easy to get on, staff was really nice. Can’t say anything about the food or entertainment because it wasn’t available, which is fine.

It was costly and difficult to check in. $85 to take a small suitcase with me, carry on or checked and $75 on the return trip, Plus $25 if I didn't check my self in check in $25, because I couldn't do it on the kiosk. Small very uncomfortable seats, waited on the runway for near an hour each way. It was my worst flight to date.

Due to weather, my flight was delayed, further delayed, then canceled. I eventually got through to a support person who helped me find a different route out of MSP, but to get to DIA, they didn't want to, but eventually did help with the connection ticket purchase. But even this replacement flight was delayed time and time again, and I would have missed my connecting flights and I didn't want to get stuck in a layover city, so after 12 hours at the airport with two young boys who were very tired, we just cancelled our plans and spent the week at home, instead of Nana's.

Horrible. I would never fly Frontier again. The booking process is tricky at best, but fraudulent in my opinion. Frontier customer service did nothing to rectify my purchase -- I ended up paying more than double what I could have gotten from other airlines and nearly triple what I thought I was buying from Frontier. Their booking practices are unfair to the consumer.

I knew going into this that Frontier, being a low cost carrier, would be pretty bare bones and charge for most extras but this was made up for by the fact that the airplane was a reasonably new Airbus, every employee was great and best of all, Everett Washington is an amazing airport - thanks Frontier for flying there!!!

I think Frontier was very good at communication. Their app worked very well. Loading was great and the flight was nice and easy.

Seats were new and comfortable. Staff was fine. Missed my connection due to weather -which wasn’t their fault- but got no help at all. Gate staff sent me to customer service, which was and stayed unstaffed. Sign with QR code directed me to call or chat. Chat was useless. Call was returned after an hour. No itinerary offered by Frontier could get me home in less than 30 hours. Rebooked with another airline and got a partial refund that came to about 10 percent of what I paid to get home.

The experience was good. No frills but I got there safe and sound and on time.

As every law enforcement agency I could imagine surrounded the plane and we didn’t disembark for 2 hours and then had to stick around for another hour to go get our personal belongings after leaving them behind and being bused away from the plane, it was scary and inconvenient. We were given no information as to why this was happening. Lack of communication with passengers was disappointing.

Everything you need to know for your flight from Phoenix to Boulder

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