Carrier route record
UADEN→MEM
United Airlines · Denver to Memphis
- Flights
- 728
- Period
- July 2025 to June 2026
- Share of route
- 55%
- Carriers
- 4
Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with United Airlines.
United on DEN to MEM 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 a little over an hour on average. That is a workable record, not a spotless one. That rests on 728 flights, with a median arrival 7 minutes early.
The US average over the same twelve months is 77.6%, so there is little to separate United on DEN to MEM from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.
Key figures
On time
81.0%
Arrivals under 15 minutes late, of 721 completed flights
Avg delay
73 min
Across delayed arrivals only, not all flights
Cancelled
0.82%
National rate is 1.81%
Whole route
75.7%
Every carrier on DEN to MEM, 1,333 flights
These figures cover 728 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
United against every carrier on DEN to MEM
United flew 728 of the 1,333 flights on DEN to MEM, most of the route. Its 81.0% on time is 5 points better than the route as a whole, which runs 75.7%. Ranked by on-time rate it is number three of four carriers on the route, where the range runs from SkyWest at 100.0% to Southwest at 65.3%. Two of those carriers flew fewer than 365 flights here, so treat their positions as rough.
Only one carrier clears this site's 365-flight floor here, so there is no comparison to draw. The table below is the full picture.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| SkyWest Airlinesthin sample | 1 | 100.0% | — | 0.00% | A+ |
| Frontier Airlinesthin sample | 139 | 82.6% | 61 min | 0.72% | B+ |
| United Airlines (this page) | 728 | 81.0% | 73 min | 0.82% | B+ |
| Southwest Airlines | 465 | 65.3% | 60 min | 0.86% | C+ |
Flight by flight
United flight numbers on DEN to MEM
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 15 points, against half a point between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am—
- 8am–11am105 flights81.9%
- 11am–2pm260 flights89.8%
- 2pm–5pm—
- 5pm–8pm363 flights74.4%
- 8pm–5am—
Scale runs 65% to 95%. Rows with fewer than 30 flights show a dash.
The best window here is not the first bank but the 11am–2pm slot at 89.8% on time, ahead of 5pm–8pm at 74.4%. Where the curve peaks mid-day rather than at dawn, the constraint is usually congestion at one end rather than the aircraft's own rotation. The 5pm–8pm window is the busiest, with 363 flights scheduled in it.
Across the year
United on DEN to MEM through the year
July is the worst month at 54.8% on time, 44 points below November, the best at 98.3%. 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. January was the busiest month here, with 62 flights.
Across the week, Sunday is the strongest day at 85.3% on time and Friday the weakest at 71.2%. 14 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 55% of the 10,000 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.
- 55%Late-arriving aircraft
- 32%Carrier
- 13%National Airspace System
- 1%Extreme weather
55% 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 10,000 reported delay minutes here, that single category outweighs weather by 55 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 10,022 reported delay minutes.
Cancellations are rare at 0.82%, 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
7.1% 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 872 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 81.2% on time across 728 flights, within half a point of this direction. The two legs are scored separately because they usually differ; on this city pair they happen not to.
One caution: this is a thin sample. 728 flights over twelve months is enough to clear this site's floor but not enough to pin the rate down tightly, and a single bad week moves it by more than a point. Treat the grade as a rough reading.
What to do with this
Booking United on DEN to MEM
Put together: treat all of this as provisional. 728 flights over twelve months is enough to clear this site's floor and not enough to be confident to better than a couple of points. The 81.0% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 721 completed flights over 12 months sit behind that.
Related
Where to go next
- DEN to MEM, every carrier
- United on MEM to DEN, the return leg
- Frontier Airlines on DEN to MEM82.6%
- Southwest Airlines on DEN to MEM65.3%
- United Airlines network-wide record
- Denver International (DEN) 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.