Carrier route record
F9DEN→PHX
Frontier Airlines · Denver to Phoenix
- Flights
- 1,432
- Period
- July 2025 to June 2026
- Share of route
- 16%
- Carriers
- 6
Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with Frontier Airlines.
Frontier on DEN to PHX lands a B+, level with the national rate of 77.6%. Roughly one flight in four arrives 15 minutes late or worse, and those flights are late by a little over an hour on average. That is a workable record, not a spotless one. That rests on 1,432 flights. The strongest carrier on the route with a full sample, United Airlines, flew 2,369 at 80.5% on time.
United Airlines is the most reliable of the three carriers covered here at 80.5% on time across 2,369 flights.
Key figures
On time
77.4%
Arrivals under 15 minutes late, of 1,421 completed flights
Avg delay
69 min
Across delayed arrivals only, not all flights
Cancelled
0.63%
National rate is 1.81%
Whole route
75.7%
Every carrier on DEN to PHX, 8,930 flights
These figures cover 1,432 flights between July 2025 and June 2026. The median arrival is 7 minutes early, which is the part an average hides: most flights here are fine, and the on-time rate is decided by a tail of badly late ones. On-time means under 15 minutes late, the DOT's own threshold.
Carrier by carrier
Frontier against every carrier on DEN to PHX
Frontier flew 1,432 of the 8,930 flights on DEN to PHX, about 16% of it. Its 77.4% on time is 2 points better than the route as a whole, which runs 75.7%. Ranked by on-time rate it is number three of six carriers on the route, where the range runs from United at 80.5% to Southwest at 72.1%. Two of those carriers flew fewer than 365 flights here, so treat their positions as rough.
The choice of carrier is not cosmetic here. United Airlines arrives on time 80.5% of the time; Southwest Airlines manages 72.1%. Sample sizes sit next to every figure, because a two-point gap across 3,950 flights means less than a ten-point one.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| United Airlines | 2,369 | 80.5% | 63 min | 0.34% | B+ |
| SkyWest Airlinesthin sample | 18 | 77.8% | 23 min | 0.00% | B+ |
| Frontier Airlines (this page) | 1,432 | 77.4% | 69 min | 0.63% | B+ |
| American Airlines | 972 | 76.9% | 120 min | 0.82% | B+ |
| Envoy Airthin sample | 189 | 72.9% | 101 min | 0.53% | C+ |
| Southwest Airlines | 3,950 | 72.1% | 56 min | 1.14% | C |
United leads Southwest by 8 points. Real, but small enough that a better departure time on the weaker carrier can outweigh it.
Flight by flight
Frontier flight numbers on DEN to PHX
Departure window
When Frontier runs best on this route
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 23 points, against 8 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am239 flights88.1%
- 8am–11am279 flights81.6%
- 11am–2pm117 flights87.1%
- 2pm–5pm165 flights78.7%
- 5pm–8pm244 flights76.4%
- 8pm–5am388 flights65.0%
Scale runs 55% to 95%. Rows with fewer than 30 flights show a dash.
Book the early departure. Flights leaving between 5am–8am arrive on time 88.1% of the time, against 65.0% for the overnight window. That is 23 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 8pm–5am window is the busiest, with 388 flights scheduled in it.
Across the year
Frontier on DEN to PHX through the year
April is the best month on the calendar at 90.4% on time. Shoulder season thins the schedule and takes the summer weather with it, and the operation gets its margin back. March was the busiest month here, with 164 flights.
Across the week, Saturday is the strongest day at 81.1% on time and Friday the weakest at 73.4%. 8 points is a smaller lever than departure hour, but it is free.
Delay causes
Why Frontier runs late on this route
Carriers report a reason for every delay minute they cause, in five DOT categories. The split below is by minutes, not by number of flights, so a handful of very long weather delays weighs as much as many short ones. It covers 22,000 reported delay minutes.
- 38%Late-arriving aircraft
- 37%Carrier
- 24%National Airspace System
- 1%Extreme weather
38% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. That is a cascade, and cascades start small and grow through the day. Across 22,000 reported delay minutes here, that single category outweighs weather by 31 to one. It is the strongest argument for booking the first departure of the morning, when the aircraft has been sitting at the gate overnight with nothing to inherit. The split is drawn from 22,070 reported delay minutes.
The largest share of delay minutes, 37%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. Unlike weather, that is a management outcome, and it is the category where the gap between two carriers on the same schedule is genuinely earned. It accounts for 8,223 of the 22,000 delay minutes reported here.
Cancellations are rare at 0.63%, below the national 1.81% and low enough to earn the plus on the grade. Roughly one flight in 100 is called off; the risk here is arriving late, not not arriving.
Connections and stage length
What a delay here costs
7.8% of arrivals land an hour or more late, close to the national 8.1%. That is the figure that decides a connection, and it says a 60 to 75 minute layover is reasonable here while anything under 45 minutes is a bet. Most delays on this route last a little over an hour, which a normal layover absorbs.
The 602 miles between these two airports put this in the middle of the US network, around two and a half to three hours of block time. That is enough cruise to absorb a ten-minute late pushback and not enough to absorb thirty. It is also long enough that the aircraft usually flies three or four legs a day rather than six, which slows how fast delay compounds.
The return leg runs 80.0% on time across 1,427 flights, within 3 points of this direction. The two legs are scored separately because they usually differ; on this city pair they happen not to.
The sample behind these figures is 1,432 flights, enough that the headline rate is stable to within roughly a point. The hour-block and month splits divide that further, so read the thinner bars with more caution than the headline.
What to do with this
Booking Frontier on DEN to PHX
Put together: the calendar is the biggest lever here, not the carrier or the hour. April runs 90.4% on time and March 69.9%, a swing of 21 points. If the dates move at all, move them out of March before you think about anything else. 1,421 completed flights over 12 months sit behind that.
Related
Where to go next
- DEN to PHX, every carrier
- Frontier on PHX to DEN, the return leg
- United Airlines on DEN to PHX80.5%
- American Airlines on DEN to PHX76.9%
- Envoy Air on DEN to PHX72.9%
- Southwest Airlines on DEN to PHX72.1%
- Frontier Airlines network-wide record
- Denver International (DEN) delay statistics
- Phoenix Sky Harbor International (PHX) delay statistics
- Why the first flight of the morning is statistically safest
- The best time of day to fly, according to 7.04 million flight records
Source: US DOT Bureau of Transportation Statistics, on-time performance data, July 2025 to June 2026. Last updated 15 September 2026; recomputed monthly. How this data is collected.