Frontier's UpFront Plus offers a guaranteed empty middle seat for added comfort.
Frontier's Zone 1 boarding is available with a carry-on or special fare bundle.

Most accurate provider | CheapOair 3 stars |
|---|---|
Most trusted provider | CheapOair 3 stars |
Round-trip from | $67 (Super.com) |
One-way from | $34 (CheapOair) |
Popular in | June |
Cheapest in | February |
Average price | $179 |
Good round-trip deal | $154 or less |
Good one-way deal | $98 or less |
Fly from
Fly to
Route
Depart
Return
Price
PhoenixDenver
PHX - DEN
PHXDEN
Phoenix Sky Harbor Intl
Sat 1/17
3:45 pm-11:58 pm
1 stop8h 13m
Denver Intl
Sun 1/18
12:34 pm-7:25 pm
1 stop6h 51m
PhoenixDenver
PHX - DEN
PHXDEN
Phoenix Sky Harbor Intl
Wed 1/14
8:24 am-11:58 pm
1 stop15h 34m
Denver Intl
Sun 1/18
8:04 am-3:03 pm
1 stop6h 59m
PhoenixDenver
PHX - DEN
PHXDEN
Phoenix Sky Harbor Intl
Thu 12/25
3:43 pm-5:39 pm
Nonstop1h 56m
Denver Intl
Tue 12/30
6:15 am-8:21 am
Nonstop2h 06m
PhoenixDenver
PHX - DEN
PHXDEN
Phoenix Sky Harbor Intl
Thu 1/15
3:45 pm-11:58 pm
1 stop8h 13m
Denver Intl
Sun 1/18
8:04 am-3:03 pm
1 stop6h 59m
PhoenixDenver
PHX - DEN
PHXDEN
Phoenix Sky Harbor Intl
Sat 12/20
9:31 am-11:26 am
Nonstop1h 55m
Denver Intl
Tue 1/6
1:26 pm-3:31 pm
Nonstop2h 05m
PhoenixDenver
PHX - DEN
PHXDEN
Phoenix Sky Harbor Intl
Tue 1/6
6:06 am-6:15 pm
2 stops12h 09m
Denver Intl
Sat 1/10
8:04 am-2:00 pm
1 stop5h 56m
PhoenixDenver
PHX - DEN
PHXDEN
Phoenix Sky Harbor Intl
Fri 1/16
3:45 pm-11:58 pm
1 stop8h 13m
Denver Intl
Wed 1/21
12:34 pm-7:25 pm
1 stop6h 51m
PhoenixDenver
PHX - DEN
PHXDEN
Phoenix Sky Harbor Intl
Sat 1/17
3:45 pm-11:58 pm
1 stop8h 13m
Denver Intl
Tue 1/20
12:34 pm-7:25 pm
1 stop6h 51m
PhoenixDenver
PHX - DEN
PHXDEN
Phoenix Sky Harbor Intl
Fri 12/19
6:04 pm-10:39 pm
1 stop4h 35m
Denver Intl
Mon 1/5
10:29 pm-12:29 am
Nonstop2h 00m
PhoenixDenver
PHX - DEN
PHXDEN
Phoenix Sky Harbor Intl
Wed 12/24
12:15 pm-7:13 pm
1 stop6h 58m
Denver Intl
Thu 12/25
6:27 pm-11:55 pm
1 stop5h 28m
| Provider | Price Accuracy | Trust Score* |
|---|---|---|
| Price Accuracy2 stars | Trust Score*3 stars | |
| Price Accuracy3 stars | Trust Score*1 star | |
| Price Accuracy3 stars | Trust Score*3 stars | |
| Price Accuracy3 stars | Trust Score*2 stars | |
| Price Accuracy- | Trust Score*1 star | |
| Price Accuracy3 stars | Trust Score*3 stars | |
| Price Accuracy1 star | Trust Score*3 stars | |
| Price Accuracy3 stars | Trust Score*3 stars | |
| Price Accuracy3 stars | Trust Score*3 stars | |
| Price Accuracy2 stars | Trust Score*3 stars |
The best time to book flights from Phoenix Sky Harbor Intl Airport to Denver is 56 days before your desired departure date. The cost of your flight will likely increase significantly if you book two weeks in advance of your flight.
Currently, February is the cheapest month in which you can book a flight from Phoenix Sky Harbor Intl Airport to Denver (average of $53). Flying from Phoenix Sky Harbor Intl Airport to Denver in July is currently the most expensive (average of $102). 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.
It’s optimal to fly from Phoenix Sky Harbor Intl Airport to Denver in the evening. By choosing this option you can save up to 63% on the cost of your flight, compared to a flight at noon.
Travelers seeking maximum savings on their Phoenix Sky Harbor Intl Airport to Denver 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.
About 16% of weekly flights between Phoenix and Denver have experienced delays in the past year, with the average delay time being 125 minutes.
Historically, flights departing in the morning are less likely to be delayed, whereas flights leaving in the early afternoon tend to experience delays more often.
Wednesday tends to have the lowest number of delays on this route, whereas Friday has historically faced a higher average of delays compared to other days of the week.
Over the last year, Frontier have had the lowest number of delays on this route, with just 12% of flights being delayed.
Comfort
Crew
Overall
Entertainment
Food
Boarding
Reviews
Thomas,Dec 2025
SEA - DEN
Comfort
Crew
Overall
Entertainment
Food
Boarding
Reviews
Thomas,Dec 2025
SEA - DEN
Comfort
Crew
Overall
Entertainment
Food
Boarding
Reviews
Thomas,Dec 2025
SEA - DEN
Comfort
Crew
Overall
Entertainment
Food
Boarding
Reviews
Thomas,Dec 2025
SEA - DEN
Comfort
Crew
Overall
Entertainment
Food
Boarding
Reviews
Thomas,Dec 2025
SEA - DEN
| Airline | Cheapest | Average | Flexibility | On-time |
|---|---|---|---|---|
| Cheapest$65 | Average$146 | FlexibilityNo cancel fee | On-time62% | |
| Cheapest$137 | Average$222 | FlexibilityNo cancel fee | On-time71% | |
| Cheapest$138 | Average$272 | FlexibilityNo cancel fee | On-time69% | |
| Cheapest$153 | Average$243 | FlexibilityNo cancel fee | On-time63% |