Route reliability record

DFW→DEN

Dallas-Fort Worth to Denver

Flights: 6,016
Period: June 2025 to May 2026
Distance: 641 mi
Carriers: 5

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, 8 points worse than the national rate of 77.4%. The late ones land a little over an hour behind schedule. That rests on 6,016 flights, of which Frontier Airlines flew 1,083 at 78.3% on time.

Frontier Airlines is the most reliable of the three carriers covered here at 78.3% on time across 1,083 flights.

On time

69.2%

Arrivals under 15 minutes late, of 5,857 completed flights

Avg delay

75 min

Across delayed arrivals only, not all flights

Cancelled

2.26%

National rate is 1.80%

Best carrier

Frontier

78.3% on time across 1,083 flights

These figures cover 6,016 flights between June 2025 and May 2026. Beyond the headline rate, 11.7% 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 DFW to DEN

The choice of carrier is not cosmetic here. Frontier Airlines arrives on time 78.3% of the time; American Airlines manages 62.3%. Sample sizes sit next to every figure, because a two-point gap across 2,967 flights means less than a ten-point one.

On-time performance by carrier on DFW to DEN
Airline	Flights	On time	Avg delay	Cancelled	Grade
SkyWest Airlinesthin sample	23	91.3%	213 min	0.00%	A+
Envoy Airthin sample	24	87.5%	56 min	0.00%	A+
Frontier Airlines	1,083	78.3%	86 min	1.66%	B
United Airlines	1,919	74.1%	77 min	1.30%	C
American Airlines	2,967	62.3%	72 min	3.13%	D−

American Airlines cancels 3.1% 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 33 points, against 16 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.

5am–8am825 flights88.5%
8am–11am1,063 flights73.8%
11am–2pm1,157 flights80.4%
2pm–5pm999 flights58.5%
5pm–8pm995 flights58.8%
8pm–5am977 flights55.8%

Scale runs 45% to 95%. Rows with fewer than 30 flights show a dash.

The 8pm–5am window is where this operation falls apart: 55.8% on time, against 88.5% 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.

Across the year

When delays peak on this route

This route's year swings by 21 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.November best, June worst

July is the worst month at 56.2% on time, 21 points below November, the best at 77.4%. 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.

Across the week, Thursday is the strongest day at 71.7% on time and Sunday the weakest at 65.8%. 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 48% of the 135,000 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
48%
Carrier
25%
National Airspace System
23%
Extreme weather
4%
Security
0%

48% 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 135,000 reported delay minutes here, that single category outweighs weather by 11 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 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 88.5% on time here.

Cancellations sit at 2.26% against a national 1.80%, which is ordinary. Diversions add another 0.38%.

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. 11.7% of arrivals land a full hour or more behind schedule, against 8.2% 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 74.8% on time across 6,021 flights, 6 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 6 points of difference.

The sample behind these figures is 6,016 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. November runs 77.4% on time and July 56.2%, a swing of 21 points. If the dates move at all, move them out of July before you think about anything else.

Common questions

DFW to DEN questions

How often is DFW to DEN delayed?

Roughly one flight in three arrive at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 30.8% of the 6,016 flights in this analysis, against 22.6% nationally. Delayed flights are late by a little over an hour on average.

Which airline is most reliable on DFW to DEN?

Frontier Airlines leads at 78.3% on time across 1,083 flights. American Airlines is at the other end on 62.3%, a gap of 16 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 DFW to DEN?

The 5am–8am departure window is the strongest at 88.5% on time. The 8pm–5am window is the weakest at 55.8%, 33 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 DFW to DEN?

July is the weakest month at 56.2% on time, compared with 77.4% in November. Across the year that is 21 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. DFW to DEN and DEN to DFW 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, June 2025 to May 2026. Updated monthly. How this data is collected.

Key figures