Route reliability record
DAL→DEN
Dallas to Denver
- Flights
- 2,966
- Period
- September 2025 to August 2026
- Distance
- 651 mi
- Carriers
- 1
This route sits in the middle of the pack with a C. About seven flights in ten arrive on time by the DOT's definition, 7 points worse than the national rate of 77.3%. The late ones land about an hour behind schedule. That rests on 2,966 DAL to DEN flights, with a median arrival right on schedule.
Best time to fly DAL to DEN: a 5am–8am departure, ideally on a Wednesday. Flights in that window arrived on time 92.7% of the time and Wednesday flights 74.7%, against 70.2% for the route overall.
The national on-time rate over the same period is 77.3%, so this route runs 7 points behind the country as a whole. Across a thousand flights that is about 71 extra late arrivals.
Key figures
On time
70.2%
Arrivals under 15 minutes late, of 2,914 completed flights
Avg delay
59 min
Across delayed arrivals only, not all flights
Cancelled
1.38%
National rate is 1.89%
Best carrier
Southwest
70.2% on time across 2,966 flights
These figures cover 2,966 flights between September 2025 and August 2026. Beyond the headline rate, 9.8% 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 DAL to DEN
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 |
|---|---|---|---|---|---|
| Southwest Airlines | 2,966 | 70.2% | 59 min | 1.38% | C |
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Best ways to make this trip
The most reliable ways to fly Dallas to Denver
Every airline on this route and on the routes between nearby airports, ranked by how often a scheduled flight actually operated and arrived on time. 3 of the top 4 use a different airport at one end.
| Option | Airline | Success | On time | Cancelled | Best departure | Most punctual flight |
|---|---|---|---|---|---|---|
| 1. DFW → DENDallas-Fort Worth to Denver | United Airlines | 76.9% | 77.7% | 1.01% | 5am–8am, Tue | UA 2049 11:05 |
| 2. DFW → DENDallas-Fort Worth to Denver | Frontier Airlines | 76.5% | 77.3% | 1.08% | 5am–8am, Sun | F9 2147 05:18 |
| 3. DAL → DENDallas to Denver | Southwest Airlines | 69.2% | 70.2% | 1.38% | 5am–8am, Wed | — |
| 4. DFW → DENDallas-Fort Worth to Denver | American Airlines | 60.9% | 62.7% | 2.90% | 5am–8am, Tue | AA 1523 07:05 |
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 39 points, against half a point between the best and worst carrier.
- 5am–8am401 flights92.7%
- 8am–11am498 flights79.6%
- 11am–2pm651 flights74.4%
- 2pm–5pm563 flights63.5%
- 5pm–8pm581 flights53.4%
- 8pm–5am272 flights58.7%
Scale runs 45% to 100%.
The 5pm–8pm window is where this operation falls apart: 53.4% on time, against 92.7% 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 651 flights scheduled in it.
Explore
Filter DAL to DEN 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 DAL to DEN, the best departure window is 5am–8am at 92.7% on time and the worst is 5pm–8pm at 53.4%, a wide gap of 39.3 points. All US flights leaving 5am–8am ran 89.3%.
- 5–8am92.7%
- 8–11am79.6%
- 11am–2pm74.4%
- 2–5pm63.5%
- 5–8pm53.4%
- 8pm–5am58.7%
best all US flightsScale 45% to 95%.
Across the year
When delays peak on this route
This route's year swings by 24 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 58.6% on time, 24 points below January, the best at 82.5%. 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. July was the busiest month here, with 272 flights.
Across the week, Wednesday is the strongest day at 74.7% on time and Thursday the weakest at 66.3%, a spread of 8 points.
Delay causes
Why this route gets delayed
Late-arriving aircraft accounts for 45% of the 51,000 delay minutes carriers reported here, and the remaining four split what is left.
- 45%Late-arriving aircraft
- 27%Carrier
- 22%National Airspace System
- 6%Extreme weather
- 0%Security
45% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 51,000 reported delay minutes here, that single category outweighs weather by 8 to one. The split is drawn from 50,836 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 92.7% on time here.
Cancellations sit at 1.38% against a national 1.89%, which is ordinary. Diversions add another 0.37%.
Connections and stage length
What a delay here actually costs
9.8% of arrivals land a full hour or more behind schedule, against 8.3% nationally. Ninety minutes is the honest minimum for a connection here, and two hours if the onward flight is on a separate ticket.
The 651 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 71.3% on time across 2,968 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 2,966 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 DEN 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. January runs 82.5% on time and June 58.6%, a swing of 24 points. If the dates move at all, move them out of June before you think about anything else. 2,914 completed flights over 12 months sit behind that.
Common questions
DAL to DEN questions
How often is DAL to DEN delayed?
Roughly one flight in three arrives at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 29.8% of the 2,966 flights in this analysis, against 22.7% nationally. Delayed flights are late by about an hour on average.
How reliable is DAL to DEN compared with the rest of the country?
70.2% of flights arrive on time here against a national 77.3%, a difference of 7 points against it. That is worth a C on this site's grading scale.
What time of day has the fewest delays on DAL to DEN?
The 5am–8am departure window is the strongest at 92.7% on time. The 5pm–8pm window is the weakest at 53.4%, 39 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 DAL to DEN?
June is the weakest month at 58.6% on time, compared with 82.5% in January. Across the year that is 24 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
- DEN to DAL — the return legseparate record
- Dallas Love Field (DAL) delay statistics
- Denver International (DEN) delay statistics
- DAL to HOU, a related route74.8%
- PHX to DEN, a related route76.7%
- DAL to ATL, a related route78.1%
- Southwest Airlines on-time record70.2%
- Why the first flight of the morning is statistically safest
- How often a connection fails at the major US hubs
Direction matters. DAL to DEN and DEN to DAL 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.