Route reliability record
DEN→LAS
Denver to Las Vegas
- Flights
- 7,168
- Period
- September 2025 to August 2026
- Distance
- 628 mi
- Carriers
- 3
This route sits in the middle of the pack with a B+. Close to three flights in four arrive on time by the DOT's definition, 2 points worse than the national rate of 77.3%. The late ones land about an hour behind schedule. That rests on 7,168 DEN to LAS flights, of which United Airlines flew 2,401 at 79.4% on time.
Best time to fly DEN to LAS: a 5am–8am departure, ideally on a Tuesday. Flights in that window arrived on time 93.5% of the time and Tuesday flights 82.4%, against 75.5% for the route overall.
United Airlines is the most reliable of the three carriers covered here at 79.4% on time across 2,401 flights.
Key figures
On time
75.5%
Arrivals under 15 minutes late, of 7,112 completed flights
Avg delay
64 min
Across delayed arrivals only, not all flights
Cancelled
0.64%
National rate is 1.89%
Best carrier
United
79.4% on time across 2,401 flights
These figures cover 7,168 flights between September 2025 and August 2026. Beyond the headline rate, 8.5% of arrivals land a full hour or more behind schedule, against 8.3% nationally.
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Carrier by carrier
Which airline is most reliable on DEN to LAS
The choice of carrier is not cosmetic here. United Airlines arrives on time 79.4% of the time; Southwest Airlines manages 72.4%. Sample sizes sit next to every figure, because a two-point gap across 3,141 flights means less than a ten-point one.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| United Airlines | 2,401 | 79.4% | 65 min | 0.33% | B+ |
| Frontier Airlines | 1,626 | 75.8% | 78 min | 1.05% | B |
| Southwest Airlines | 3,141 | 72.4% | 58 min | 0.67% | C+ |
United leads Southwest by 7 points. Real, but small enough that a better departure time on the weaker carrier can outweigh it.
Flight by flight
Flights on DEN to LAS
The flight numbers below flew this route at least 250 times in the period, busiest first. Each has its own record, with its schedule and delay causes.
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Best ways to make this trip
The most reliable ways to fly Denver to Las Vegas
Every airline on this route, ranked by how often a scheduled flight actually operated and arrived on time, with its best departure time and most punctual flight number. No nearby airport pair beat these.
| Option | Airline | Success | On time | Cancelled | Best departure | Most punctual flight |
|---|---|---|---|---|---|---|
| 1. DEN → LASDenver to Las Vegas | United Airlines | 79.1% | 79.4% | 0.33% | 5am–8am, Tue | UA 2316 07:45 |
| 2. DEN → LASDenver to Las Vegas | Frontier Airlines | 75.0% | 75.8% | 1.05% | 5am–8am, Sat | F9 2015 07:00 |
| 3. DEN → LASDenver to Las Vegas | Southwest Airlines | 71.9% | 72.4% | 0.67% | 5am–8am, Tue | — |
Success is the share of scheduled flights that operated and arrived less than 15 minutes late, so a cancelled flight counts against it. “(route)” means the best time comes from every carrier on the route rather than this airline alone.
Departure window
The best time of day to leave
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 30 points, against 7 points between the best and worst carrier.
- 5am–8am883 flights93.5%
- 8am–11am1,337 flights87.6%
- 11am–2pm1,432 flights77.8%
- 2pm–5pm1,140 flights67.3%
- 5pm–8pm1,282 flights63.1%
- 8pm–5am1,094 flights66.0%
Scale runs 55% to 100%.
The 5pm–8pm window is where this operation falls apart: 63.1% on time, against 93.5% for the 5am–8am slot. By evening the aircraft flying these rotations have absorbed a full day of small delays and there is no slack left to recover in. The 11am–2pm window is the busiest, with 1,432 flights scheduled in it.
Explore
Filter DEN to LAS by airline, time, month and day
Pick a breakdown and a carrier. The dashed mark on each row is the same slice for every US flight.
On DEN to LAS, the best departure window is 5am–8am at 93.5% on time and the worst is 5pm–8pm at 63.1%, a wide gap of 30.4 points. All US flights leaving 5am–8am ran 89.3%.
- 5–8am93.5%
- 8–11am87.6%
- 11am–2pm77.8%
- 2–5pm67.3%
- 5–8pm63.1%
- 8pm–5am66.0%
best all US flightsScale 55% to 100%.
Across the year
When delays peak on this route
This route's year swings by 19 points from best month to worst, which is wide. An annual average tells you very little about the week you are actually flying, so read the strip rather than the headline if your dates are fixed.
June is the worst month at 65.4% on time, 19 points below February, the best at 84.2%. 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 666 flights.
Across the week, Tuesday is the strongest day at 82.4% on time and Thursday the weakest at 69.2%, a spread of 13 points.
Delay causes
Why this route gets delayed
Late-arriving aircraft accounts for 49% of the 112,000 delay minutes carriers reported here, and the remaining four split what is left.
- 49%Late-arriving aircraft
- 26%Carrier
- 23%National Airspace System
- 2%Extreme weather
- 0%Security
49% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 112,000 reported delay minutes here, that single category outweighs weather by 23 to one. The split is drawn from 111,627 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 93.5% on time here.
Cancellations are rare at 0.64%, below the national 1.89% 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 actually costs
8.5% 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 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.
The return leg runs 76.5% on time across 7,140 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.
The sample behind these figures is 7,168 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.
Work out the risk of missing a connection in LAS after this flight
What to do with this
Booking this route
Put together: the calendar is the biggest lever here, not the carrier or the hour. February runs 84.2% on time and June 65.4%, a swing of 19 points. If the dates move at all, move them out of June before you think about anything else. 7,112 completed flights over 12 months sit behind that.
Common questions
DEN to LAS questions
How often is DEN to LAS delayed?
About one flight in four arrives at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 24.5% of the 7,168 flights in this analysis, against 22.7% nationally. Delayed flights are late by about an hour on average.
Which airline is most reliable on DEN to LAS?
United Airlines leads at 79.4% on time across 2,401 flights. Southwest Airlines is at the other end on 72.4%, a gap of 7 points. Sample size matters as much as the percentage: a rate built from a few hundred flights moves around far more than one built from ten thousand.
What time of day has the fewest delays on DEN to LAS?
The 5am–8am departure window is the strongest at 93.5% on time. The 5pm–8pm window is the weakest at 63.1%, 30 points behind. Later departures inherit delays from earlier flights the same aircraft has already flown, which is why the curve slopes the way it does.
How bad are June delays on DEN to LAS?
June is the weakest month at 65.4% on time, compared with 84.2% in February. Across the year that is 19 points between the best and worst months. Moving flexible dates out of that month is one of the few things that reliably helps.
Related
Where to go next
- LAS to DEN — the return legseparate record
- Denver International (DEN) delay statistics
- Harry Reid International (LAS) delay statistics
- United Airlines on DEN to LAS79.4%
- Frontier Airlines on DEN to LAS75.8%
- Southwest Airlines on DEN to LAS72.4%
- DEN to PHX, a related route75.6%
- LAX to LAS, a related route75.8%
- DEN to SLC, a related route78.2%
- United Airlines on-time record79.4%
- Frontier Airlines on-time record75.8%
- Southwest Airlines on-time record72.4%
- Why the first flight of the morning is statistically safest
- The best time of day to fly, according to 7.05 million flight records
Direction matters. DEN to LAS and LAS to DEN are scored separately because they are separate operations, with different departure banks and different aircraft. Compare the return leg.
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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.