Carrier route record
UAMEM→DEN
United Airlines · Memphis to Denver
- Flights
- 727
- Period
- September 2025 to August 2026
- Share of route
- 52%
- Carriers
- 4
Historical statistics for September 2025 to August 2026, not live status. For today’s flights, check with United Airlines.
United on MEM to DEN lands a B+, 4 points better than the national rate of 77.3%. Roughly one flight in five arrives 15 minutes late or worse, and those flights are late by a little over an hour on average. That rests on 727 flights, with a median arrival 8 minutes early.
Set against the rest of the country, United's MEM to DEN record is 4 points better than the US average of 77.3%. That gap is worth roughly 43 fewer late arrivals for every thousand flights.
Key figures
On time
81.6%
Arrivals under 15 minutes late, of 718 completed flights
Avg delay
81 min
Across delayed arrivals only, not all flights
Cancelled
0.96%
National rate is 1.89%
Whole route
77.7%
Every carrier on MEM to DEN, 1,395 flights
These figures cover 727 flights between September 2025 and August 2026. The median arrival is 8 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.
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Carrier by carrier
United against every carrier on MEM to DEN
United flew 727 of the 1,395 flights on MEM to DEN, most of the route. Its 81.6% on time is 4 points better than the route as a whole, which runs 77.7%. Ranked by on-time rate it is number two of four carriers on the route, where the range runs from SkyWest at 100.0% to Southwest at 72.8%. 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+ |
| United Airlines (this page) | 727 | 81.6% | 81 min | 0.96% | B+ |
| Frontier Airlinesthin sample | 145 | 75.5% | 89 min | 0.69% | B+ |
| Southwest Airlines | 522 | 72.8% | 58 min | 0.57% | C+ |
Timetable by Aviasales, a Travelpayouts partner. Booking through it may earn this site a commission at no cost to you; it changes no figure here.
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 14 points, against half a point between the best and worst carrier.
- 5am–8am—
- 8am–11am364 flights88.4%
- 11am–2pm—
- 2pm–5pm363 flights74.8%
- 5pm–8pm—
- 8pm–5am—
Scale runs 65% to 95%. Rows with fewer than 30 flights show a dash.
Book the morning departure. Flights leaving between 8am–11am arrive on time 88.4% of the time, against 74.8% for the afternoon window. That is 14 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 8am–11am window is the busiest, with 364 flights scheduled in it.
Across the year
United on MEM to DEN through the year
August is the worst month at 63.9% on time, 33 points below November, the best at 96.6%. 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, Friday is the strongest day at 84.5% on time and Saturday the weakest at 77.2%, a spread of 7 points.
Arrival by arrival
How late United on MEM to DEN runs when it is late
United on MEM to DEN often beats the schedule: 213 of 718 completed flights, 30%, arrived 15 minutes or more early. The 132 late arrivals split 43 under half an hour, 38 between 30 and 60 minutes, and 51 an hour or more.
- 15+ min early213 flights29.7%
- Within 15 min373 flights51.9%
- 15–29 min late43 flights6.0%
- 30–59 min late38 flights5.3%
- 1–2 hours late28 flights3.9%
- 2+ hours late23 flights3.2%
Scale runs 0% to 100%.
Share of 718 completed flights by arrival against schedule.
25 of 123 late departures made up the time and arrived on time, 20% of them. 34 flights left on time and still arrived late.
The worst days
Worst days for United on MEM to DEN
The latest arrival of the period was on 23 April 2026, 18 hours 26 minutes behind schedule; most of its delay minutes were filed as carrier-caused (crew, maintenance, fuelling, baggage). The same cause led on three of the five worst days.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 23 April 2026 | 18 hours 26 minutes | Carrier |
| 13 February 2026 | 6 hours 39 minutes | Carrier |
| 7 December 2025 | 6 hours 33 minutes | Late-arriving aircraft |
| 22 July 2026 | 5 hours 40 minutes | National Airspace System |
| 14 April 2026 | 4 hours 27 minutes | Carrier |
Delay causes
Why United runs late on this route
National Airspace System accounts for 45% of the 11,000 delay minutes carriers reported here, and the remaining four split what is left.
- 45%National Airspace System
- 37%Carrier
- 15%Late-arriving aircraft
- 2%Extreme weather
The largest share of delay minutes, 37%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. It accounts for 4,009 of the 11,000 delay minutes reported here. The split is drawn from 10,693 reported delay minutes.
45% of delay minutes are charged to the National Airspace System: air traffic volume, runway configuration, ground stops. No carrier can price its way out of that, which is why airport choice moves the number here more than carrier choice does. That is 4,864 minutes out of 11,000, against a national NAS share of 21%.
Cancellations sit at 0.96% against a national 1.89%, which is ordinary. Diversions add another 0.28%.
Connections and stage length
What a delay here costs
7.1% of arrivals land an hour or more late, close to the national 8.3%, so 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.
The return leg runs 82.9% on time across 727 flights, within about 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. 727 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 MEM to DEN
Put together: treat all of this as provisional. 727 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 81.6% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 718 completed flights over 12 months sit behind that.
Related
Where to go next
- MEM to DEN, every carrier
- United on DEN to MEM, the return leg
- Frontier Airlines on MEM to DEN75.5%
- Southwest Airlines on MEM to DEN72.8%
- United Airlines network-wide record
- Memphis International (MEM) delay statistics
- Denver International (DEN) delay statistics
- The best time of day to fly, according to 7.05 million flight records
- Worst months to fly in the US, ranked by the data
Source: US DOT Bureau of Transportation Statistics, on-time performance data, September 2025 to August 2026. Last updated ; recomputed monthly. How this data is collected.