Route reliability record

DFW→IAH

Dallas-Fort Worth to Houston

Flights: 5,774
Period: June 2025 to May 2026
Distance: 224 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 5,774 flights, of which Envoy Air flew 885 at 78.6% on time.

Envoy Air is the most reliable of the three carriers covered here at 78.6% on time across 885 flights.

On time

69.8%

Arrivals under 15 minutes late, of 5,593 completed flights

Avg delay

79 min

Across delayed arrivals only, not all flights

Cancelled

2.94%

National rate is 1.80%

Best carrier

Envoy

78.6% on time across 885 flights

These figures cover 5,774 flights between June 2025 and May 2026. Beyond the headline rate, 11.9% 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 IAH

The choice of carrier is not cosmetic here. Envoy Air arrives on time 78.6% of the time; American Airlines manages 60.0%. Sample sizes sit next to every figure, because a two-point gap across 2,454 flights means less than a ten-point one.

On-time performance by carrier on DFW to IAH
Airline	Flights	On time	Avg delay	Cancelled	Grade
Envoy Air	885	78.6%	53 min	3.16%	B−
SkyWest Airlinesthin sample	37	77.8%	95 min	2.70%	B
PSA Airlinesthin sample	9	77.8%	113 min	0.00%	B+
United Airlines	2,389	76.4%	84 min	2.18%	B
American Airlines	2,454	60.0%	81 min	3.63%	D−

American Airlines cancels 3.6% 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 21 points, against 19 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.

5am–8am1,009 flights80.0%
8am–11am995 flights77.1%
11am–2pm598 flights74.9%
2pm–5pm1,328 flights68.7%
5pm–8pm1,231 flights59.5%
8pm–5am613 flights58.6%

Scale runs 50% to 85%. Rows with fewer than 30 flights show a dash.

The 8pm–5am window is where this operation falls apart: 58.6% on time, against 80.0% 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 28 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.February best, June worst

June is the worst month at 58.4% on time, 28 points below February, the best at 86.4%. 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, Tuesday is the strongest day at 75.3% on time and Sunday the weakest at 64.7%. 11 points is a smaller lever than departure hour, but it is free.

Delay causes

Why this route gets delayed

Carriers report a reason for every delay minute they cause, in five DOT categories. The split below is by minutes, not by number of flights, so a handful of very long weather delays weighs as much as many short ones. It covers 133,000 reported delay minutes.

Late-arriving aircraft
42%
Carrier
26%
National Airspace System
25%
Extreme weather
7%

42% 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 133,000 reported delay minutes here, that single category outweighs weather by 6 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 80.0% on time here.

Cancellations run at 2.94%, against 1.80% nationally. That is roughly one flight in 30 cancelled outright. A cancelled flight is invisible in every on-time figure on this page, so the punctuality numbers above describe only the flights that actually operated.

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. 11.9% 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.

At 224 miles this is a short hop, and stage length matters more than it looks. A flight this short spends under two hours in the air, which leaves almost nothing to claw back a late pushback with. Delay here is decided on the ground, in the turn, which is why the 5am–8am window matters as much as it does.

The return leg is a different operation and performs like one: it runs 74.8% on time across 5,773 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 5,774 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 delay figures matter less here than the 2.94% cancellation rate. A late arrival costs you a little over an hour; a cancelled flight costs you the day. Book the 5am–8am departure so there is still a schedule behind you if it goes wrong, and treat a same-day connection as optimistic.

Common questions

DFW to IAH questions

How often is DFW to IAH 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 30.2% of the 5,774 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 IAH?

Envoy Air leads at 78.6% on time across 885 flights. American Airlines is at the other end on 60.0%, a gap of 19 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 IAH?

The 5am–8am departure window is the strongest at 80.0% on time. The 8pm–5am window is the weakest at 58.6%, 21 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 DFW to IAH?

June is the weakest month at 58.4% on time, compared with 86.4% in February. Across the year that is 28 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 IAH and IAH 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