Carrier route record
UADEN→LAS
United Airlines · Denver to Las Vegas
- Flights
- 2,420
- Period
- July 2025 to June 2026
- Share of route
- 34%
- Carriers
- 3
Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with United Airlines.
United on DEN to LAS lands a B+, about a point 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 2,420 flights. The strongest carrier on the route with a full sample, Frontier Airlines, flew 1,557 at 76.3% on time.
The US average over the same twelve months is 77.6%, so there is little to separate United on DEN to LAS from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.
Key figures
On time
78.6%
Arrivals under 15 minutes late, of 2,406 completed flights
Avg delay
66 min
Across delayed arrivals only, not all flights
Cancelled
0.37%
National rate is 1.81%
Whole route
75.3%
Every carrier on DEN to LAS, 7,108 flights
These figures cover 2,420 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 LAS
United flew 2,420 of the 7,108 flights on DEN to LAS, about 34% of it. Its 78.6% on time is 3 points better than the route as a whole, which runs 75.3%. Ranked by on-time rate it is first of three carriers on the route, where the range runs from United at 78.6% to Southwest at 72.3%.
The two carriers here are closely matched: 4 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) | 2,420 | 78.6% | 66 min | 0.37% | B+ |
| Frontier Airlines | 1,557 | 76.3% | 71 min | 0.96% | B+ |
| Southwest Airlines | 3,131 | 72.3% | 57 min | 0.73% | C+ |
No carrier stands out. Frontier tops the table at 76.3%, 4 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 LAS
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 25 points, against 4 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am190 flights93.7%
- 8am–11am331 flights91.2%
- 11am–2pm637 flights83.7%
- 2pm–5pm401 flights73.1%
- 5pm–8pm561 flights69.1%
- 8pm–5am300 flights69.6%
Scale runs 60% to 100%. Rows with fewer than 30 flights show a dash.
Book the early departure. Flights leaving between 5am–8am arrive on time 93.7% of the time, against 69.1% for the evening window. That is 25 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 637 flights scheduled in it.
Across the year
United on DEN to LAS through the year
July is the worst month at 54.4% on time, 33 points below April, the best at 87.7%. 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. October was the busiest month here, with 237 flights.
Across the week, Wednesday is the strongest day at 83.3% on time and Thursday the weakest at 72.3%. 11 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 46% of the 34,000 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.
- 46%Late-arriving aircraft
- 27%National Airspace System
- 22%Carrier
- 5%Extreme weather
46% 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 34,000 reported delay minutes here, that single category outweighs weather by 10 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 34,110 reported delay minutes.
The practical consequence: the 5am–8am departure is the one that starts clean. Its aircraft has no earlier leg to be late from, which is exactly why that window shows 93.7% on time here.
Cancellations are rare at 0.37%, 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
7.9% 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 628 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 83.7% on time across 2,416 flights, 5 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 5 points of difference.
The sample behind these figures is 2,420 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 LAS
Put together: the calendar is the biggest lever here, not the carrier or the hour. April runs 87.7% on time and July 54.4%, a swing of 33 points. If the dates move at all, move them out of July before you think about anything else. 2,406 completed flights over 12 months sit behind that.
Related
Where to go next
- DEN to LAS, every carrier
- United on LAS to DEN, the return leg
- Frontier Airlines on DEN to LAS76.3%
- Southwest Airlines on DEN to LAS72.3%
- United Airlines network-wide record
- Denver International (DEN) delay statistics
- Harry Reid International (LAS) 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.