Route reliability record
DFW→IAH
Dallas-Fort Worth to Houston
- Flights
- 5,780
- Period
- July 2025 to June 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 77.6%. The late ones land a little over an hour behind schedule. That rests on 5,780 flights, of which Envoy Air flew 840 at 78.0% on time.
Envoy Air is the most reliable of the three carriers covered here at 78.0% on time across 840 flights.
Key figures
On time
69.8%
Arrivals under 15 minutes late, of 5,604 completed flights
Avg delay
81 min
Across delayed arrivals only, not all flights
Cancelled
2.92%
National rate is 1.81%
Best carrier
Envoy
78.0% on time across 840 flights
These figures cover 5,780 flights between July 2025 and June 2026. Beyond the headline rate, 12.0% 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 78.0% of the time; American Airlines manages 59.7%. Sample sizes sit next to every figure, because a two-point gap across 2,465 flights means less than a ten-point one.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| Envoy Air | 840 | 78.0% | 55 min | 2.98% | B |
| SkyWest Airlinesthin sample | 53 | 77.6% | 98 min | 7.55% | B− |
| United Airlines | 2,414 | 76.9% | 86 min | 1.99% | B |
| PSA Airlinesthin sample | 8 | 75.0% | 113 min | 0.00% | B+ |
| American Airlines | 2,465 | 59.7% | 83 min | 3.73% | D− |
American Airlines cancels 3.7% 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 22 points, against 18 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am1,007 flights79.8%
- 8am–11am1,001 flights75.8%
- 11am–2pm623 flights74.2%
- 2pm–5pm1,317 flights68.7%
- 5pm–8pm1,232 flights60.9%
- 8pm–5am600 flights57.9%
Scale runs 50% to 85%. Rows with fewer than 30 flights show a dash.
The 8pm–5am window is where this operation falls apart: 57.9% on time, against 79.8% 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 2pm–5pm window is the busiest, with 1,317 flights scheduled in it.
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.
June is the worst month at 58.1% 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. April was the busiest month here, with 523 flights.
Across the week, Tuesday is the strongest day at 75.9% on time and Sunday the weakest at 63.7%. 12 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 44% of the 137,000 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.
- 44%Late-arriving aircraft
- 26%Carrier
- 23%National Airspace System
- 7%Extreme weather
- 0%Security
44% 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 137,000 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 split is drawn from 136,993 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 79.8% on time here.
Cancellations run at 2.92%, against 1.81% 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. 12.0% 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.
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 75.0% on time across 5,779 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 5,780 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 2.92% 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. 5,604 completed flights over 12 months sit behind that.
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 5,780 flights in this analysis, against 22.4% 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 78.0% on time across 840 flights. American Airlines is at the other end on 59.7%, a gap of 18 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 79.8% on time. The 8pm–5am window is the weakest at 57.9%, 22 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 58.1% 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.
Related
Where to go next
- IAH to DFW — the return legseparate record
- Dallas/Fort Worth International (DFW) delay statistics
- George Bush Intercontinental (IAH) delay statistics
- Envoy Air on-time record78.0%
- SkyWest Airlines on-time record77.6%
- United Airlines on-time record76.9%
- Why the first flight of the morning is statistically safest
- The best time of day to fly, according to 7.04 million flight records
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, July 2025 to June 2026. Updated monthly. How this data is collected.