Carrier route record
DLLAX→IAH
Delta Air Lines · Los Angeles to Houston
- Flights
- 648
- Period
- September 2025 to August 2026
- Share of route
- 13%
- Carriers
- 5
Historical statistics for September 2025 to August 2026, not live status. For today’s flights, check with Delta Air Lines.
Delta on LAX to IAH earns a B+. More than four flights in five arrive inside the 15-minute window the DOT uses to define an on-time arrival, which puts it 8 points better than the national rate of 77.3%. When something does go wrong the average delay runs a little over an hour. That rests on 648 flights. The strongest carrier on the route with a full sample, United Airlines, flew 3,420 at 87.4% on time.
Set against the rest of the country, Delta's LAX to IAH record is 8 points better than the US average of 77.3%. That gap is worth roughly 75 fewer late arrivals for every thousand flights.
Key figures
On time
84.8%
Arrivals under 15 minutes late, of 640 completed flights
Avg delay
70 min
Across delayed arrivals only, not all flights
Cancelled
0.93%
National rate is 1.89%
Whole route
84.6%
Every carrier on LAX to IAH, 5,143 flights
These figures cover 648 flights between September 2025 and August 2026. The median arrival is 7 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.
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Carrier by carrier
Delta against every carrier on LAX to IAH
Delta flew 648 of the 5,143 flights on LAX to IAH, about 13% of it. Its 84.8% on time is about level with the route as a whole at 84.6%. Ranked by on-time rate it is number two of five carriers on the route, where the range runs from United at 87.4% to Frontier at 70.6%. Two 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 87.4% of the time; SkyWest Airlines manages 81.2%. Sample sizes sit next to every figure, because a two-point gap across 408 flights means less than a ten-point one.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| United Airlines | 3,420 | 87.4% | 52 min | 0.18% | A+ |
| Delta Air Lines (this page) | 648 | 84.8% | 70 min | 0.93% | B+ |
| SkyWest Airlines | 408 | 81.2% | 70 min | 0.49% | B+ |
| Spirit Airlinesthin sample | 331 | 73.0% | 73 min | 1.51% | C |
| Frontier Airlinesthin sample | 336 | 70.6% | 74 min | 1.49% | C |
United leads SkyWest by 6 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
Timetable by Aviasales, a Travelpayouts partner. Booking through it may earn this site a commission at no cost to you; it changes no figure here.
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 648 flights.
- 5am–8am—
- 8am–11am365 flights85.6%
- 11am–2pm—
- 2pm–5pm—
- 5pm–8pm283 flights83.9%
- 8pm–5am—
Scale runs 75% to 90%. Rows with fewer than 30 flights show a dash.
The 8am–11am window is the strongest at 85.6% on time. The full set of windows spans 2 points.
Across the year
Delta on LAX to IAH through the year
July is the worst month at 72.7% on time, 21 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, Monday is the strongest day at 92.2% on time and Saturday the weakest at 71.4%, a spread of 21 points.
Arrival by arrival
How late Delta on LAX to IAH runs when it is late
Delta on LAX to IAH often beats the schedule: 187 of 640 completed flights, 29%, arrived 15 minutes or more early. The 97 late arrivals split 33 under half an hour, 28 between 30 and 60 minutes, and 36 an hour or more.
- 15+ min early187 flights29.2%
- Within 15 min356 flights55.6%
- 15–29 min late33 flights5.2%
- 30–59 min late28 flights4.4%
- 1–2 hours late22 flights3.4%
- 2+ hours late14 flights2.2%
Scale runs 0% to 100%.
Share of 640 completed flights by arrival against schedule.
18 of 93 late departures made up the time and arrived on time, 19% of them. 22 flights left on time and still arrived late.
The worst days
Worst days for Delta on LAX to IAH
The latest arrival of the period was on 23 December 2025, 6 hours 55 minutes behind schedule; most of its delay minutes were filed as carrier-caused (crew, maintenance, fuelling, baggage). The same cause led on three of the five worst days.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 23 December 2025 | 6 hours 55 minutes | Carrier |
| 1 April 2026 | 6 hours 42 minutes | Carrier |
| 18 September 2025 | 5 hours 4 minutes | Carrier |
| 3 January 2026 | 4 hours 30 minutes | Late-arriving aircraft |
| 22 May 2026 | 4 hours 16 minutes | Late-arriving aircraft |
Delay causes
Why Delta runs late on this route
Carrier accounts for 52% of the 6,744 delay minutes carriers reported here, and the remaining four split what is left.
- 52%Carrier
- 30%Late-arriving aircraft
- 18%National Airspace System
The largest share of delay minutes, 52%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. It accounts for 3,496 of the 6,744 delay minutes reported here. The split is drawn from 6,744 reported delay minutes.
The practical consequence: the 8am–11am departure is the one that starts clean. Its aircraft has no earlier leg to be late from, which is exactly why that window shows 85.6% on time here.
Cancellations sit at 0.93% against a national 1.89%, which is ordinary. Diversions add another 0.31%.
Connections and stage length
What a delay here costs
5.6% of arrivals land an hour or more late, close to the national 8.3%, so 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.
The return leg runs 87.7% on time across 648 flights, within 3 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. 648 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. 648 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 84.8% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 640 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 IAH87.4%
- SkyWest Airlines on LAX to IAH81.2%
- Spirit Airlines on LAX to IAH73.0%
- Frontier Airlines on LAX to IAH70.6%
- 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, September 2025 to August 2026. Last updated ; recomputed monthly. How this data is collected.