Carrier route record
DLLGA→IAH
Delta Air Lines · New York to Houston
- Flights
- 1,342
- Period
- July 2025 to June 2026
- Share of route
- 33%
- Carriers
- 4
Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with Delta Air Lines.
Delta on LGA to IAH carries a cancellation problem, not just a delay problem: 3.7% of scheduled flights never operate, against 1.8% nationally. Of the ones that do fly, close to three flights in four arrive on time, worth a C− overall. The punctuality figure counts only flights that actually departed, so it flatters an operation that cancels this often. That rests on 1,342 flights, with a median arrival 12 minutes early.
The US average over the same twelve months is 77.6%, so there is little to separate Delta on LGA to IAH from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.
Key figures
On time
74.5%
Arrivals under 15 minutes late, of 1,284 completed flights
Avg delay
85 min
Across delayed arrivals only, not all flights
Cancelled
3.73%
National rate is 1.81%
Whole route
76.5%
Every carrier on LGA to IAH, 4,060 flights
These figures cover 1,342 flights between July 2025 and June 2026. Beyond the headline rate, 11.8% 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
Delta against every carrier on LGA to IAH
Delta flew 1,342 of the 4,060 flights on LGA to IAH, about 33% of it. Its 74.5% on time is 2 points worse than the route as a whole, which runs 76.5%. Ranked by on-time rate it is last of four carriers on the route, where the range runs from SkyWest at 80.6% to Delta at 74.5%. Two of those carriers flew fewer than 365 flights here, so treat their positions as rough.
Only one carrier clears this site's 365-flight floor here, so there is no comparison to draw. The table below is the full picture.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| SkyWest Airlinesthin sample | 32 | 80.6% | 38 min | 3.12% | B− |
| Spirit Airlinesthin sample | 304 | 79.8% | 65 min | 3.95% | B− |
| United Airlines | 2,382 | 77.1% | 87 min | 1.76% | B |
| Delta Air Lines (this page) | 1,342 | 74.5% | 85 min | 3.73% | C− |
Flight by flight
Delta flight numbers on LGA to IAH
Departure window
When Delta runs best on this route
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 28 points, against half a point between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am289 flights88.8%
- 8am–11am343 flights76.6%
- 11am–2pm239 flights70.0%
- 2pm–5pm156 flights78.0%
- 5pm–8pm315 flights60.9%
- 8pm–5am—
Scale runs 50% to 95%. Rows with fewer than 30 flights show a dash.
The 5pm–8pm window is where this operation falls apart: 60.9% on time, against 88.8% 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 8am–11am window is the busiest, with 343 flights scheduled in it.
Across the year
Delta on LGA to IAH through the year
December is the weak month at 56.1% on time, against 87.2% in February. Winter delays cluster: a single storm system can account for most of a month's shortfall, so an average December hides both very good weeks and genuinely unflyable days. May was the busiest month here, with 118 flights.
Across the week, Tuesday is the strongest day at 78.6% on time and Sunday the weakest at 68.4%. 10 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 51% of the 28,000 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.
- 51%Carrier
- 25%National Airspace System
- 22%Late-arriving aircraft
- 2%Extreme weather
- 0%Security
The largest share of delay minutes, 51%, 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 14,000 of the 28,000 delay minutes reported here. The split is drawn from 27,879 reported delay minutes.
Cancellations run at 3.73%, against 1.81% nationally. That is about one flight in 25 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 costs
For anyone connecting, the number to weigh is not the on-time rate but the tail behind it. 11.8% 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.
The 1,416 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 77.2% on time across 1,342 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.
The sample behind these figures is 1,342 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 Delta on LGA to IAH
Put together: the delay figures matter less here than the 3.73% 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. 1,284 completed flights over 12 months sit behind that.
Related
Where to go next
- LGA to IAH, every carrier
- Delta on IAH to LGA, the return leg
- Spirit Airlines on LGA to IAH79.8%
- United Airlines on LGA to IAH77.1%
- Delta Air Lines network-wide record
- LaGuardia (LGA) delay statistics
- George Bush Intercontinental (IAH) delay statistics
- The US routes with the most cancellations
- The best time of day to fly, according to 7.04 million flight records
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.