Carrier route record
UADEN→PHX
United Airlines · Denver to Phoenix
- Flights
- 2,369
- Period
- July 2025 to June 2026
- Share of route
- 27%
- Carriers
- 6
Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with United Airlines.
United on DEN to PHX lands a B+, 3 points better than the national rate of 77.6%. About one flight in five arrives 15 minutes late or worse, and those flights are late by about an hour on average. That is a workable record, not a spotless one. That rests on 2,369 flights. The strongest carrier on the route with a full sample, Frontier Airlines, flew 1,432 at 77.4% on time.
The US average over the same twelve months is 77.6%, so there is little to separate United on DEN to PHX from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.
Key figures
On time
80.5%
Arrivals under 15 minutes late, of 2,358 completed flights
Avg delay
63 min
Across delayed arrivals only, not all flights
Cancelled
0.34%
National rate is 1.81%
Whole route
75.7%
Every carrier on DEN to PHX, 8,930 flights
These figures cover 2,369 flights between July 2025 and June 2026. The median arrival is 6 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
United against every carrier on DEN to PHX
United flew 2,369 of the 8,930 flights on DEN to PHX, about 27% of it. Its 80.5% on time is 5 points better than the route as a whole, which runs 75.7%. Ranked by on-time rate it is first 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 three carriers here are closely matched: 5 points separate the best from the worst. At that spread, schedule and price are better tie-breakers than reliability. Sample sizes are shown so you can see which rows are worth weighing.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| United Airlines (this page) | 2,369 | 80.5% | 63 min | 0.34% | B+ |
| SkyWest Airlinesthin sample | 18 | 77.8% | 23 min | 0.00% | B+ |
| Frontier Airlines | 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 |
No carrier stands out. Frontier tops the table at 77.4%, 5 points clear of the bottom, which is inside the range this kind of sample moves year to year.
Flight by flight
United flight numbers on DEN to PHX
Departure window
When United runs best on this route
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 17 points, against 5 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am243 flights83.1%
- 8am–11am308 flights87.9%
- 11am–2pm571 flights85.2%
- 2pm–5pm427 flights80.4%
- 5pm–8pm516 flights75.7%
- 8pm–5am304 flights70.6%
Scale runs 60% to 95%. Rows with fewer than 30 flights show a dash.
Book the morning departure. Flights leaving between 8am–11am arrive on time 87.9% of the time, against 70.6% for the overnight window. That is 17 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 11am–2pm window is the busiest, with 571 flights scheduled in it.
Across the year
United on DEN to PHX through the year
July is the worst month at 56.2% on time, 33 points below April, the best at 89.3%. Summer afternoon convection and peak-season schedules land on the same weeks every year, so this is a pattern you can book around rather than a run of bad luck. March was the busiest month here, with 249 flights.
Across the week, Tuesday is the strongest day at 87.1% on time and Thursday the weakest at 78.2%. 9 points is a smaller lever than departure hour, but it is free.
Delay causes
Why United runs late on this route
One category carries most of the weight here. Late-arriving aircraft accounts for 54% of the 29,000 delay minutes carriers reported, and the remaining four split what is left. The split is by minutes rather than by flights, so a few very long delays count for as much as many short ones.
- 54%Late-arriving aircraft
- 23%Carrier
- 21%National Airspace System
- 2%Extreme weather
54% 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 29,000 reported delay minutes here, that single category outweighs weather by 27 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 29,022 reported delay minutes.
The practical consequence: the 8am–11am departure is the one that starts clean. Its aircraft has no earlier leg to be late from, which is exactly why that window shows 87.9% on time here.
Cancellations are rare at 0.34%, 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
7.0% 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 about 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 is a different operation and performs like one: it runs 83.5% on time across 2,370 flights, 3 points above this direction. Departure banks, aircraft rotations and the congestion at each end all differ, so scoring the two directions together would average away a real 3 points of difference.
The sample behind these figures is 2,369 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 United on DEN to PHX
Put together: the calendar is the biggest lever here, not the carrier or the hour. April runs 89.3% on time and July 56.2%, a swing of 33 points. If the dates move at all, move them out of July before you think about anything else. 2,358 completed flights over 12 months sit behind that.
Related
Where to go next
- DEN to PHX, every carrier
- United on PHX to DEN, the return leg
- Frontier Airlines on DEN to PHX77.4%
- American Airlines on DEN to PHX76.9%
- Envoy Air on DEN to PHX72.9%
- Southwest Airlines on DEN to PHX72.1%
- United 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.