Route reliability record

DEN→DFW

Denver to Dallas-Fort Worth

Flights: 6,029
Period: July 2025 to June 2026
Distance: 641 mi
Carriers: 5

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, 3 points worse than the national rate of 77.6%. The late ones land an hour and a half behind schedule. That rests on 6,029 flights, of which United Airlines flew 1,902 at 77.2% on time.

United Airlines is the most reliable of the three carriers covered here at 77.2% on time across 1,902 flights.

On time

75.0%

Arrivals under 15 minutes late, of 5,874 completed flights

Avg delay

85 min

Across delayed arrivals only, not all flights

Cancelled

2.07%

National rate is 1.81%

Best carrier

United

77.2% on time across 1,902 flights

These figures cover 6,029 flights between July 2025 and June 2026. Beyond the headline rate, 10.1% of arrivals land a full hour or more behind schedule. That is the number that wrecks a connection, and it is not visible in an on-time percentage alone.

Carrier by carrier

Which airline is most reliable on DEN to DFW

The three 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.

On-time performance by carrier on DEN to DFW
Airline	Flights	On time	Avg delay	Cancelled	Grade
SkyWest Airlinesthin sample	23	91.3%	79 min	0.00%	A+
United Airlines	1,902	77.2%	69 min	0.79%	B+
Frontier Airlines	1,125	75.2%	71 min	0.80%	B+
Envoy Airthin sample	24	75.0%	81 min	0.00%	B+
American Airlines	2,955	73.3%	100 min	3.42%	C−

American Airlines cancels 3.4% of what it schedules here, the highest in the table. A cancelled flight never appears in an on-time rate, so read that column alongside the punctuality one rather than after it.

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 28 points, against 4 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.

5am–8am1,271 flights88.1%
8am–11am1,674 flights80.8%
11am–2pm624 flights71.1%
2pm–5pm1,067 flights68.2%
5pm–8pm862 flights60.0%
8pm–5am531 flights66.9%

Scale runs 50% to 95%. Rows with fewer than 30 flights show a dash.

The 5pm–8pm window is where this operation falls apart: 60.0% on time, against 88.1% 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 8am–11am window is the busiest, with 1,674 flights scheduled in it.

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.

Darker means more delays. Figures are on-time percentages.April best, July worst

July is the worst month at 62.5% on time, 19 points below April, the best at 81.5%. 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. March was the busiest month here, with 541 flights.

Across the week, Wednesday is the strongest day at 77.5% on time and Sunday the weakest at 71.3%. 6 points is a smaller lever than departure hour, but it is free.

Delay causes

Why this route gets delayed

One category carries most of the weight here. Late-arriving aircraft accounts for 49% of the 126,000 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.

Late-arriving aircraft
49%
Carrier
29%
National Airspace System
18%
Extreme weather
4%
Security
0%

49% 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 126,000 reported delay minutes here, that single category outweighs weather by 13 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 125,501 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 88.1% on time here.

Cancellations sit at 2.07% against a national 1.81%, which is ordinary. Diversions add another 0.50%.

Connections and stage length

What a delay here actually costs

For anyone connecting, the number to weigh is not the on-time rate but the tail behind it. 10.1% of arrivals land a full hour or more behind schedule, against 8.1% nationally. A 45-minute layover does not survive that, and no amount of walking quickly changes it. Ninety minutes is the honest minimum here, and two hours if the onward flight is on a separate ticket.

The 641 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 69.4% on time across 6,025 flights, 6 points below 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 6 points of difference.

The sample behind these figures is 6,029 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 this route

Put together: the calendar is the biggest lever here, not the carrier or the hour. April runs 81.5% on time and July 62.5%, a swing of 19 points. If the dates move at all, move them out of July before you think about anything else. 5,874 completed flights over 12 months sit behind that.

Common questions

DEN to DFW questions

How often is DEN to DFW delayed?

About one flight in four arrive at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 25.0% of the 6,029 flights in this analysis, against 22.4% nationally. Delayed flights are late by an hour and a half on average.

Which airline is most reliable on DEN to DFW?

United Airlines leads at 77.2% on time across 1,902 flights. American Airlines is at the other end on 73.3%, a gap of 4 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 DFW?

The 5am–8am departure window is the strongest at 88.1% on time. The 5pm–8pm window is the weakest at 60.0%, 28 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 July delays on DEN to DFW?

July is the weakest month at 62.5% on time, compared with 81.5% in April. 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.

Where to go next

Direction matters. DEN to DFW and DFW to DEN are scored separately because they are separate operations, with different departure banks and different aircraft. Compare the return leg.

Source: US DOT Bureau of Transportation Statistics, on-time performance data, July 2025 to June 2026. Updated monthly. How this data is collected.

Key figures