Route reliability record
IAH→DFW
Houston to Dallas-Fort Worth
- Flights
- 5,779
- Period
- July 2025 to June 2026
- Distance
- 224 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 5,779 flights, of which Envoy Air flew 840 at 78.1% on time.
Envoy Air is the most reliable of the three carriers covered here at 78.1% on time across 840 flights.
Key figures
On time
75.0%
Arrivals under 15 minutes late, of 5,606 completed flights
Avg delay
99 min
Across delayed arrivals only, not all flights
Cancelled
2.80%
National rate is 1.81%
Best carrier
Envoy
78.1% on time across 840 flights
These figures cover 5,779 flights between July 2025 and June 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 IAH to DFW
The three carriers here are closely matched: 5 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.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| SkyWest Airlinesthin sample | 53 | 79.2% | 58 min | 9.43% | B− |
| Envoy Air | 840 | 78.1% | 100 min | 3.10% | B− |
| United Airlines | 2,415 | 75.7% | 74 min | 1.70% | B |
| American Airlines | 2,464 | 73.2% | 121 min | 3.65% | C− |
| PSA Airlinesthin sample | 7 | 57.1% | 428 min | 0.00% | 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 23 points, against 5 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am1,273 flights84.4%
- 8am–11am962 flights79.0%
- 11am–2pm733 flights78.7%
- 2pm–5pm1,146 flights71.8%
- 5pm–8pm1,017 flights61.1%
- 8pm–5am648 flights74.1%
Scale runs 55% to 90%. Rows with fewer than 30 flights show a dash.
The 5pm–8pm window is where this operation falls apart: 61.1% on time, against 84.4% 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 5am–8am window is the busiest, with 1,273 flights scheduled in it.
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.
August is the worst month at 64.0% on time, 21 points below February, the best at 85.4%. 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 524 flights.
Across the week, Tuesday is the strongest day at 79.2% on time and Sunday the weakest at 69.8%. 9 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 42% of the 139,000 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.
- 42%Late-arriving aircraft
- 27%Carrier
- 19%National Airspace System
- 12%Extreme weather
Extreme weather accounts for 12% of delay minutes, well above the single-digit share typical across the system. Weather delays are lumpy: they arrive as whole bad days rather than as a steady drag, so the monthly strip above is the more useful view of the risk. The national share is 6%, so this operation carries roughly 1.9 times the usual weather exposure. The split is drawn from 138,886 reported delay minutes.
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 139,000 reported delay minutes here, that single category outweighs weather by 3 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.
Cancellations run at 2.80%, against 1.81% nationally. That is roughly one flight in 40 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. 11.7% 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 69.8% on time across 5,780 flights, 5 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 5 points of difference.
The sample behind these figures is 5,779 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 2.80% cancellation rate. A late arrival costs you an hour and a half; 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. 5,606 completed flights over 12 months sit behind that.
Common questions
IAH to DFW questions
How often is IAH 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 5,779 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 IAH to DFW?
Envoy Air leads at 78.1% on time across 840 flights. American Airlines is at the other end on 73.2%, a gap of 5 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 IAH to DFW?
The 5am–8am departure window is the strongest at 84.4% on time. The 5pm–8pm window is the weakest at 61.1%, 23 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 August delays on IAH to DFW?
August is the weakest month at 64.0% on time, compared with 85.4% in February. 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.
Related
Where to go next
- DFW to IAH — the return legseparate record
- George Bush Intercontinental (IAH) delay statistics
- Dallas/Fort Worth International (DFW) delay statistics
- SkyWest Airlines on-time record79.2%
- Envoy Air on-time record78.1%
- United Airlines on-time record75.7%
- 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. IAH to DFW and DFW to IAH 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.