$49+ Cheap flights from Sky Harbor Intl (PHX) to Boulder, CO
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 2/24. Fares are subject to change and may not be available on all flights or dates of travel.
PHX — DEN
Mar 22 — Mar 291
1 adult, Economy
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Find cheap flights from Sky Harbor Intl to Boulder with Cheapflights
1. Tell us where you want to go
Enter your travel information like dates, passengers, trip type (one-way or round trip), and preferred cabin class then click “Find deals”2. Select your favorite providers
We find the providers serving your travel needs. Choose up to four travel providers to compare side-by-side for flights, hotels, or car rentals.3. Compare prices and book
Review each provider’s pricing and select the best option for you! Book through your favorite provider’s website for a seamless experience.Cheapflights Tip: The best prices from Phoenix Sky Harbor Intl to Boulder are usually found in February or October, booked 78 days in advance, depart on a Thursday or Friday and return on a Wednesday
Cheap flight deals from Sky Harbor Intl to Boulder
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Best
Last-minute
One-way
Cheapest flights from Sky Harbor Intl to BoulderExplore the most affordable flight options available from Sky Harbor Intl to Boulder. Find the lowest fares from popular airlines and budget airlines, with prices last updated on February 20, 2026.
Explore the most affordable flight options available from Sky Harbor Intl to Boulder. Find the lowest fares from popular airlines and budget airlines, with prices last updated on February 20, 2026.
This Kiwi.com deal was found by Cheapflights users on 2/19. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 4/176:50 am
PHX
- DEN
Nonstop1h 53m
Frontier
Mon 4/207:11 pm
DEN
- PHX
Nonstop2h 05m
Frontier
Deal found 2/19![Frontier logo]()
$65
This Frontier deal was found by Cheapflights users on 2/19. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 4/279:24 pm
PHX
- DEN
Nonstop1h 56m
Frontier
Mon 5/47:11 pm
DEN
- PHX
Nonstop2h 05m
Frontier
Deal found 2/19![Frontier logo]()
$66
This Super.com deal was found by Cheapflights users on 2/17. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Super.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 3/46:51 pm
PHX
- DEN
Nonstop1h 55m
Frontier
Tue 3/1010:39 am
DEN
- PHX
Nonstop2h 15m
Frontier
Deal found 2/17![Frontier logo]()
$67
This Kiwi.com deal was found by Cheapflights users on 2/17. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 3/239:24 pm
PHX
- DEN
Nonstop1h 54m
Frontier
Tue 3/244:36 pm
DEN
- PHX
Nonstop2h 10m
Frontier
Deal found 2/17![Frontier logo]()
$69
This Frontier deal was found by Cheapflights users on 2/20. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 3/2412:54 pm
PHX
- DEN
Nonstop1h 52m
Frontier
Mon 3/3010:40 pm
DEN
- PHX
Nonstop2h 11m
Frontier
Deal found 2/20![Frontier logo]()
$71
This Kiwi.com deal was found by Cheapflights users on 2/19. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 4/309:24 pm
PHX
- DEN
Nonstop1h 56m
Frontier
Fri 5/110:40 pm
DEN
- PHX
Nonstop2h 07m
Frontier
Deal found 2/19![Frontier logo]()
$74
This Frontier deal was found by Cheapflights users on 2/18. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 4/308:52 am
PHX
- DEN
Nonstop1h 59m
Frontier
Thu 4/3010:40 pm
DEN
- PHX
Nonstop2h 07m
Frontier
Deal found 2/18![Frontier logo]()
$75
This Cheapflightsfares deal was found by Cheapflights users on 2/18. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 5/136:50 am
PHX
- DEN
Nonstop1h 53m
Frontier
Sun 5/1710:40 pm
DEN
- PHX
Nonstop2h 07m
Frontier
Deal found 2/18![Frontier logo]()
$76
This Kiwi.com deal was found by Cheapflights users on 2/19. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 3/710:24 pm
PHX
- DEN
Nonstop1h 51m
Frontier
Wed 3/1112:49 pm
DEN
- PHX
Nonstop2h 12m
Frontier
Deal found 2/19![Frontier logo]()
$77
This Frontier deal was found by Cheapflights users on 2/20. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 3/273:11 pm
PHX
- DEN
Nonstop1h 54m
Frontier
Tue 3/3112:49 pm
DEN
- PHX
Nonstop2h 12m
Frontier
Deal found 2/20![Frontier logo]()
$78
Best flights from Sky Harbor Intl to BoulderDiscover carefully curated flight deals from Sky Harbor Intl to Boulder that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated February 20, 2026.
Discover carefully curated flight deals from Sky Harbor Intl to Boulder that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated February 20, 2026.
This Kiwi.com deal was found by Cheapflights users on 2/17. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 3/239:24 pm
PHX
- DEN
Nonstop1h 54m
Frontier
Tue 3/244:36 pm
DEN
- PHX
Nonstop2h 10m
Frontier
Deal found 2/17![Frontier logo]()
$69
This Alaska Airlines deal was found by Cheapflights users on 2/20. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 4/286:37 am
PHX
- DEN
1 stop4h 29m
Alaska Airlines
Wed 5/61:02 pm
DEN
- PHX
1 stop6h 24m
Alaska Airlines
Deal found 2/20![Alaska Airlines logo]()
$137
This Expedia deal was found by Cheapflights users on 2/16. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Expedia is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 4/111:45 pm
PHX
- DEN
1 stop10h 16m
Multiple Airlines
Tue 4/146:20 pm
DEN
- PHX
1 stop6h 07m
Multiple Airlines
Deal found 2/16![Multiple Airlines logo]()
$154
This Super.com deal was found by Cheapflights users on 2/16. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Super.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 4/116:52 pm
PHX
- DEN
Nonstop1h 53m
Frontier
Tue 4/144:36 pm
DEN
- PHX
Nonstop2h 07m
Frontier
Deal found 2/16![Frontier logo]()
$84
This Cheapflightsfares deal was found by Cheapflights users on 2/16. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 5/158:52 am
PHX
- DEN
Nonstop1h 59m
Frontier
Sun 5/1710:40 pm
DEN
- PHX
Nonstop2h 07m
Frontier
Deal found 2/16![Frontier logo]()
$86
This Cheapflightsfares deal was found by Cheapflights users on 2/16. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 4/216:50 am
PHX
- DEN
Nonstop1h 53m
Frontier
Sun 5/35:15 am
DEN
- PHX
1 stop7h 44m
Frontier
Deal found 2/16![Frontier logo]()
$102
This Alaska Airlines deal was found by Cheapflights users on 2/19. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 4/286:37 am
PHX
- DEN
1 stop4h 29m
Alaska Airlines
Wed 4/291:02 pm
DEN
- PHX
1 stop6h 24m
Alaska Airlines
Deal found 2/19![Alaska Airlines logo]()
$137
This Frontier deal was found by Cheapflights users on 2/17. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 3/239:24 pm
PHX
- DEN
Nonstop1h 54m
Frontier
Wed 3/2512:54 pm
DEN
- PHX
1 stop9h 20m
Frontier
Deal found 2/17![Frontier logo]()
$122
This Cheapflightsfares deal was found by Cheapflights users on 2/16. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 2/2810:51 pm
PHX
- DEN
Nonstop1h 51m
Frontier
Mon 3/29:27 am
DEN
- PHX
1 stop4h 47m
Frontier
Deal found 2/16![Frontier logo]()
$143
This Cheapflightsfares deal was found by Cheapflights users on 2/16. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 4/187:27 am
PHX
- DEN
1 stop8h 37m
Frontier
Mon 4/206:00 am
DEN
- PHX
1 stop5h 08m
Frontier
Deal found 2/16![Frontier logo]()
$159
This Cheapflightsfares deal was found by Cheapflights users on 2/16. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 4/96:00 am
PHX
- DEN
1 stop5h 28m
Frontier
Sun 4/127:10 pm
DEN
- PHX
1 stop15h 38m
Frontier
Deal found 2/16![Frontier logo]()
$159
This Cheapflightsfares deal was found by Cheapflights users on 2/16. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 3/129:24 pm
PHX
- DEN
Nonstop1h 54m
Frontier
Sat 3/147:05 pm
DEN
- PHX
Nonstop2h 09m
Frontier
Deal found 2/16![Frontier logo]()
$165
Last-minute flights from Sky Harbor Intl to BoulderDiscover last-minute flight deals from Sky Harbor Intl to Boulder. Data last updated February 20, 2026 and is based on user searches.
Discover last-minute flight deals from Sky Harbor Intl to Boulder. Data last updated February 20, 2026 and is based on user searches.
This Super.com deal was found by Cheapflights users on 2/19. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Super.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 2/2810:51 pm
PHX
- DEN
Nonstop1h 51m
Frontier
Tue 3/33:09 pm
DEN
- PHX
Nonstop2h 10m
Frontier
Deal found 2/19![Frontier logo]()
$79
This Frontier deal was found by Cheapflights users on 2/18. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 3/310:12 am
PHX
- DEN
Nonstop1h 56m
Frontier
Tue 3/33:09 pm
DEN
- PHX
Nonstop2h 10m
Frontier
Deal found 2/18![Frontier logo]()
$75
This Super.com deal was found by Cheapflights users on 2/17. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Super.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 3/46:51 pm
PHX
- DEN
Nonstop1h 55m
Frontier
Tue 3/1010:39 am
DEN
- PHX
Nonstop2h 15m
Frontier
Deal found 2/17![Frontier logo]()
$67
This Kiwi.com deal was found by Cheapflights users on 2/19. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 3/710:24 pm
PHX
- DEN
Nonstop1h 51m
Frontier
Wed 3/1112:49 pm
DEN
- PHX
Nonstop2h 12m
Frontier
Deal found 2/19![Frontier logo]()
$77
This Frontier deal was found by Cheapflights users on 2/20. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 3/146:55 pm
PHX
- DEN
Nonstop1h 55m
Frontier
Thu 4/210:55 pm
DEN
- PHX
Nonstop2h 07m
Frontier
Deal found 2/20![Frontier logo]()
$76
This Frontier deal was found by Cheapflights users on 2/20. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 3/168:52 am
PHX
- DEN
Nonstop1h 57m
Frontier
Tue 3/3110:40 pm
DEN
- PHX
Nonstop2h 11m
Frontier
Deal found 2/20![Frontier logo]()
$65
This Kiwi.com deal was found by Cheapflights users on 2/17. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 3/239:24 pm
PHX
- DEN
Nonstop1h 54m
Frontier
Tue 3/244:36 pm
DEN
- PHX
Nonstop2h 10m
Frontier
Deal found 2/17![Frontier logo]()
$69
This Frontier deal was found by Cheapflights users on 2/20. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 3/2412:54 pm
PHX
- DEN
Nonstop1h 52m
Frontier
Mon 3/3010:40 pm
DEN
- PHX
Nonstop2h 11m
Frontier
Deal found 2/20![Frontier logo]()
$71
This Frontier deal was found by Cheapflights users on 2/20. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 3/269:24 pm
PHX
- DEN
Nonstop1h 54m
Frontier
Tue 3/3110:39 am
DEN
- PHX
Nonstop2h 15m
Frontier
Deal found 2/20![Frontier logo]()
$66
This Frontier deal was found by Cheapflights users on 2/20. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 3/273:11 pm
PHX
- DEN
Nonstop1h 54m
Frontier
Tue 3/3112:49 pm
DEN
- PHX
Nonstop2h 12m
Frontier
Deal found 2/20![Frontier logo]()
$78
One-way flights from Sky Harbor Intl to BoulderSearch for one-way flight options from Sky Harbor Intl to Boulder. Find affordable one-way fares based on user searches. Data last updated February 20, 2026.
Search for one-way flight options from Sky Harbor Intl to Boulder. Find affordable one-way fares based on user searches. Data last updated February 20, 2026.
This CheapOair deal was found by Cheapflights users on 2/16. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure CheapOair is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 2/246:00 am
PHX
- DEN
Nonstop1h 54m
Frontier
Deal found 2/16![Frontier logo]()
$49
This Kiwi.com deal was found by Cheapflights users on 2/19. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 3/168:04 pm
PHX
- DEN
1 stop12h 56m
Frontier
Deal found 2/19![Frontier logo]()
$52
This Kiwi.com deal was found by Cheapflights users on 2/20. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 4/106:50 am
PHX
- DEN
Nonstop1h 53m
Frontier
Deal found 2/20![Frontier logo]()
$53
This Super.com deal was found by Cheapflights users on 2/20. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Super.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 4/33:11 pm
PHX
- DEN
Nonstop1h 58m
Frontier
Deal found 2/20![Frontier logo]()
$54
This Kiwi.com deal was found by Cheapflights users on 2/18. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 3/238:04 pm
PHX
- DEN
1 stop12h 56m
Frontier
Deal found 2/18![Frontier logo]()
$55
This Super.com deal was found by Cheapflights users on 2/20. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Super.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 5/109:24 pm
PHX
- DEN
Nonstop1h 56m
Frontier
Deal found 2/20![Frontier logo]()
$57
This Kiwi.com deal was found by Cheapflights users on 2/20. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 4/235:03 pm
PHX
- DEN
1 stop15h 59m
Frontier
Deal found 2/20![Frontier logo]()
$59
This Kiwi.com deal was found by Cheapflights users on 2/20. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 4/65:45 am
PHX
- DEN
1 stop18h 16m
Frontier
Deal found 2/20![Frontier logo]()
$60
This Kiwi.com deal was found by Cheapflights users on 2/20. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 4/138:15 pm
PHX
- DEN
1 stop13h 32m
Frontier
Deal found 2/20![Frontier logo]()
$61
This Kiwi.com deal was found by Cheapflights users on 2/20. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 5/411:18 am
PHX
- DEN
1 stop15h 41m
Frontier
Deal found 2/20![Frontier logo]()
$62
This Kiwi.com deal was found by Cheapflights users on 2/19. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 3/510:51 pm
PHX
- DEN
Nonstop1h 51m
Frontier
Deal found 2/19![Frontier logo]()
$63
Find flight deals from Sky Harbor Intl to Boulder
Keep the following information in mind while searching for Sky Harbor Intl to Boulder flight deals. Data was last updated February 20, 2026.
Round-trip from | $65 (Frontier) |
|---|---|
One-way from | $49 (CheapOair) |
Popular in | June |
Cheapest in | February |
Average price | $148 |
Cheapflights Fare Finder
Customize your flight search to find flights from Sky Harbor Intl to Boulder that fit within your specific budget. Explore options based on user searches and filter the results based on your desired price range. Find flights that match your budget for a cost-effective journey. Over the last 7 days, Cheapflights users made 2,558,603 searches. Data last updated February 20, 2026.
Use the filters below to find and compare flights from Phoenix Sky Harbor Intl Airport to Boulder that are best for you.
Fly from
Sky Harbor Intl
Fly to
Boulder
Route
Depart
Return
Price
PhoenixDenver
PHX - DEN
PHXDEN
Phoenix Sky Harbor Intl
Mon 3/23
9:24 pm-12:18 am
Nonstop1h 54m
Denver Intl
Tue 3/24
4:36 pm-5:46 pm
Nonstop2h 10m
$69
PhoenixDenver
PHX - DEN
PHXDEN
Phoenix Sky Harbor Intl
Sat 4/11
6:52 pm-9:45 pm
Nonstop1h 53m
Denver Intl
Tue 4/14
4:36 pm-5:43 pm
Nonstop2h 07m
$84
PhoenixDenver
PHX - DEN
PHXDEN
Phoenix Sky Harbor Intl
Fri 5/15
8:52 am-11:51 am
Nonstop1h 59m
Denver Intl
Sun 5/17
10:40 pm-11:47 pm
Nonstop2h 07m
$86
PhoenixDenver
PHX - DEN
PHXDEN
Phoenix Sky Harbor Intl
Tue 4/21
6:50 am-9:43 am
Nonstop1h 53m
Denver Intl
Sun 5/3
5:15 am-11:59 am
1 stop7h 44m
$102
PhoenixDenver
PHX - DEN
PHXDEN
Phoenix Sky Harbor Intl
Mon 3/23
9:24 pm-12:18 am
Nonstop1h 54m
Denver Intl
Wed 3/25
12:54 pm-9:14 pm
1 stop9h 20m
$122
PhoenixDenver
PHX - DEN
PHXDEN
Phoenix Sky Harbor Intl
Tue 4/28
6:37 am-12:06 pm
1 stop4h 29m
Denver Intl
Wed 5/6
1:02 pm-6:26 pm
1 stop6h 24m
$137
PhoenixDenver
PHX - DEN
PHXDEN
Phoenix Sky Harbor Intl
Tue 4/28
6:37 am-12:06 pm
1 stop4h 29m
Denver Intl
Wed 4/29
1:02 pm-6:26 pm
1 stop6h 24m
$137
PhoenixDenver
PHX - DEN
PHXDEN
Phoenix Sky Harbor Intl
Sat 2/28
10:51 pm-12:42 am
Nonstop1h 51m
Denver Intl
Mon 3/2
9:27 am-2:14 pm
1 stop4h 47m
$143
PhoenixDenver
PHX - DEN
PHXDEN
Phoenix Sky Harbor Intl
Sat 4/11
1:45 pm-1:01 am
1 stop10h 16m
Denver Intl
Tue 4/14
6:20 pm-11:27 pm
1 stop6h 07m
$154
PhoenixDenver
PHX - DEN
PHXDEN
Phoenix Sky Harbor Intl
Sat 4/18
7:27 am-5:04 pm
1 stop8h 37m
Denver Intl
Mon 4/20
6:00 am-10:08 am
1 stop5h 08m
$159
Showing 1-10 of 24 results
Best time to book a flight from Sky Harbor Intl to Boulder
Have a flexible travel schedule? Discover the best time to fly to Boulder from Sky Harbor Intl with our price prediction graph.
PHX-DEN
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 from Phoenix Sky Harbor Intl Airport to Boulder
PHX-BD9
PHX-DEN
How far ahead should I book a flight from Phoenix Sky Harbor Intl Airport to Boulder?
Use this chart to determine the optimal time to book a round-trip flight from Sky Harbor Intl to Boulder. Price data was last updated on February 18, 2026.
To ensure you get the cheapest price possible for a flight from Phoenix Sky Harbor Intl Airport to Boulder, you should look to book at least 71 days in advance of your intended travel date. The price of your flight may increase if you delay and leave booking until a week or so before departure.
What is the cheapest month to book a flight from Phoenix Sky Harbor Intl Airport to Boulder?
Currently, January is the cheapest month in which you can book a flight from Phoenix Sky Harbor Intl Airport to Boulder (average of $58). Flying from Phoenix Sky Harbor Intl Airport to Boulder in July is currently the most expensive (average of $103). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.
What is the cheapest time of day to fly from PHX to BD9?
Find hourly flight availability from Sky Harbor Intl to Boulder. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated February 20, 2026.
A simple way to save on the total cost of your ticket is to fly from Phoenix Sky Harbor Intl Airport to Boulder in the evening. If you’re flexible enough to do this you can expect to save up to 49% on your trip compared to booking a flight at noon.
What is the cheapest day to fly from Phoenix Sky Harbor Intl Airport to Boulder?
Use this chart to determine the cheapest time to fly round-trip from Sky Harbor Intl to Boulder. Price data was last updated on February 17, 2026.
Travelers seeking maximum savings on their Phoenix Sky Harbor Intl Airport to Boulder flight should consider departing on Friday evenings when fares are most often at their lowest. Sunday at noon flights should be avoided if possible as fares are typically the most expensive at this time.
Weekly flight availability from Phoenix Sky Harbor Intl Airport to Boulder
Explore weekly flight availability from Sky Harbor Intl to Boulder. Discover flights operating on different days of the week, giving you the flexibility to choose a travel day that best fits your plans. Compare info to find the most convenient option for your journey. Data last updated February 20, 2026.
The most flights from PHX to BD9 are scheduled on a Thursday (59 on average). You will have fewer flight options on Saturday, which is when the least amount of flights are scheduled (22 on average).
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 February 20, 2026.
Read through reviews of airlines operating flights from Phoenix Sky Harbor Intl Airport to Boulder, such as Southwest, United Airlines, and American Airlines. Reviews also offer insight into each airline's entertainment options, comfort, food, crew/service, and boarding process.
Crew
8.6
Comfort
8.0
Entertainment
7.5
Overall
8.0
Boarding
8.1
Food
7.0
Reviews
1 / 20
2.0
MediocreThomas,Dec 2025
SEA - DEN
Crew
8.6
Comfort
8.0
Entertainment
7.5
Overall
8.0
Boarding
8.1
Food
7.0
Reviews
1 / 20
2.0
MediocreThomas,Dec 2025
SEA - DEN
Crew
8.6
Comfort
8.0
Entertainment
7.5
Overall
8.0
Boarding
8.1
Food
7.0
Reviews
1 / 20
2.0
MediocreThomas,Dec 2025
SEA - DEN
Crew
8.6
Comfort
8.0
Entertainment
7.5
Overall
8.0
Boarding
8.1
Food
7.0
Reviews
1 / 20
2.0
MediocreThomas,Dec 2025
SEA - DEN
Crew
8.6
Comfort
8.0
Entertainment
7.5
Overall
8.0
Boarding
8.1
Food
7.0
Reviews
1 / 20
2.0
MediocreThomas,Dec 2025
SEA - DEN
Related info for your journey
Find useful and relevant information for your journey from Sky Harbor Intl to Boulder. Access travel guides, tips, and recommendations to enhance your travel experience. Get information about local attractions, weather, transportation options, and more.
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Sky Harbor Intl and Boulder flights
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Other flights from Sky Harbor Intl
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Top 5 airlines flying from Sky Harbor Intl to Boulder
Discover the top 5 airlines that operate flights from Sky Harbor Intl to Boulder. Compare their services, reliability, and customer satisfaction ratings to choose the airline that best suits your travel preferences and needs. Over the last 7 days, Cheapflights users made 2,558,603 searches. Data last updated February 20, 2026.
| Airline | Cheapest | Average | Flexibility | On-time |
|---|---|---|---|---|
| Cheapest$63 | Average$148 | FlexibilityNo cancel fee | On-time62% | |
| Cheapest$134 | Average$304 | FlexibilityNo cancel fee | On-time69% | |
| Cheapest$137 | Average$224 | FlexibilityNo cancel fee | On-time71% | |
| Cheapest$149 | Average$274 | FlexibilityNo cancel fee | On-time63% | |
| Cheapest$206 | Average$278 | FlexibilityNo cancel fee | On-timeN/A |