Carrier route record
DLLAX→IAH
Delta Air Lines · Los Angeles to Houston
- Flights
- 645
- Period
- July 2025 to June 2026
- Share of route
- 12%
- Carriers
- 5
Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with Delta Air Lines.
Delta on LAX to IAH earns an A. More than four flights in five arrive inside the 15-minute window the DOT uses to define an on-time arrival, which puts it 9 points better than the national rate of 77.6%. When something does go wrong the average delay runs a little over an hour. That rests on 645 flights. The strongest carrier on the route with a full sample, United Airlines, flew 3,415 at 87.1% on time.
United Airlines is the most reliable of the three carriers covered here at 87.1% on time across 3,415 flights.
Key figures
On time
86.1%
Arrivals under 15 minutes late, of 633 completed flights
Avg delay
73 min
Across delayed arrivals only, not all flights
Cancelled
1.09%
National rate is 1.81%
Whole route
84.6%
Every carrier on LAX to IAH, 5,255 flights
These figures cover 645 flights between July 2025 and June 2026. The median arrival is 9 minutes early, which is the part an average hides: most flights here are fine, and the on-time rate is decided by a tail of badly late ones. On-time means under 15 minutes late, the DOT's own threshold.
Carrier by carrier
Delta against every carrier on LAX to IAH
Delta flew 645 of the 5,255 flights on LAX to IAH, about 12% of it. Its 86.1% on time is 2 points better than the route as a whole, which runs 84.6%. Ranked by on-time rate it is number two of five carriers on the route, where the range runs from United at 87.1% to Frontier at 68.2%. One of those carriers flew fewer than 365 flights here, so treat their positions as rough.
The choice of carrier is not cosmetic here. United Airlines arrives on time 87.1% of the time; Spirit Airlines manages 77.5%. Sample sizes sit next to every figure, because a two-point gap across 455 flights means less than a ten-point one.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| United Airlines | 3,415 | 87.1% | 55 min | 0.26% | A+ |
| Delta Air Lines (this page) | 645 | 86.1% | 73 min | 1.09% | A |
| SkyWest Airlines | 408 | 82.0% | 68 min | 0.49% | B+ |
| Spirit Airlines | 455 | 77.5% | 83 min | 1.32% | B |
| Frontier Airlinesthin sample | 332 | 68.2% | 71 min | 2.11% | C |
United leads Spirit by 10 points. Real, but small enough that a better departure time on the weaker carrier can outweigh it.
Flight by flight
Delta flight numbers on LAX to IAH
Departure window
When Delta runs best on this route
Departure time is the single lever a traveller controls, and it moves the odds more than most people expect. Each bar below is the on-time rate for flights scheduled to leave inside that window, across 645 flights.
- 5am–8am—
- 8am–11am365 flights87.2%
- 11am–2pm—
- 2pm–5pm—
- 5pm–8pm280 flights84.7%
- 8pm–5am—
Scale runs 75% to 95%. Rows with fewer than 30 flights show a dash.
The 8am–11am window is the strongest at 87.2% on time. The full set of windows spans 3 points.
Across the year
Delta on LAX to IAH through the year
June is the worst month at 78.8% on time, 15 points below September, the best at 94.1%. 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 58 flights.
Across the week, Thursday is the strongest day at 92.9% on time and Saturday the weakest at 73.2%. 20 points is a smaller lever than departure hour, but it is free.
Delay causes
Why Delta runs late on this route
One category carries most of the weight here. Carrier accounts for 57% of the 6,424 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.
- 57%Carrier
- 26%Late-arriving aircraft
- 18%National Airspace System
The largest share of delay minutes, 57%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. Unlike weather, that is a management outcome, and it is the category where the gap between two carriers on the same schedule is genuinely earned. It accounts for 3,638 of the 6,424 delay minutes reported here. The split is drawn from 6,424 reported delay minutes.
Cancellations sit at 1.09% against a national 1.81%, which is ordinary. Diversions add another 0.78%.
Connections and stage length
What a delay here costs
5.2% of arrivals land an hour or more late, close to the national 8.1%. That is the figure that decides a connection, and it says a 60 to 75 minute layover is reasonable here while anything under 45 minutes is a bet. Most delays on this route last a little over an hour, which a normal layover absorbs.
The 1,379 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 runs 88.5% on time across 645 flights, within 2 points of this direction. The two legs are scored separately because they usually differ; on this city pair they happen not to.
One caution: this is a thin sample. 645 flights over twelve months is enough to clear this site's floor but not enough to pin the rate down tightly, and a single bad week moves it by more than a point. Treat the grade as a rough reading.
What to do with this
Booking Delta on LAX to IAH
Put together: treat all of this as provisional. 645 flights over twelve months is enough to clear this site's floor and not enough to be confident to better than a couple of points. The 86.1% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 633 completed flights over 12 months sit behind that.
Related
Where to go next
- LAX to IAH, every carrier
- Delta on IAH to LAX, the return leg
- United Airlines on LAX to IAH87.1%
- SkyWest Airlines on LAX to IAH82.0%
- Spirit Airlines on LAX to IAH77.5%
- Frontier Airlines on LAX to IAH68.2%
- Delta Air Lines network-wide record
- Los Angeles International (LAX) delay statistics
- George Bush Intercontinental (IAH) delay statistics
- Worst months to fly in the US, ranked by the data
- How to read this site: grades, sample sizes, and honest caveats
Source: US DOT Bureau of Transportation Statistics, on-time performance data, July 2025 to June 2026. Last updated 15 September 2026; recomputed monthly. How this data is collected.