Carrier route record
DLIAH→LGA
Delta Air Lines · Houston to New York
- 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 IAH to LGA carries a cancellation problem, not just a delay problem: 4.0% 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 B− 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 7 minutes early.
The US average over the same twelve months is 77.6%, so there is little to separate Delta on IAH to LGA from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.
Key figures
On time
77.2%
Arrivals under 15 minutes late, of 1,277 completed flights
Avg delay
95 min
Across delayed arrivals only, not all flights
Cancelled
3.95%
National rate is 1.81%
Whole route
72.6%
Every carrier on IAH to LGA, 4,053 flights
These figures cover 1,342 flights between July 2025 and June 2026. Beyond the headline rate, 9.5% 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 IAH to LGA
Delta flew 1,342 of the 4,053 flights on IAH to LGA, about 33% of it. Its 77.2% on time is 5 points better than the route as a whole, which runs 72.6%. Ranked by on-time rate it is number two of four carriers on the route, where the range runs from SkyWest at 83.9% to Spirit at 60.6%. 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 | 83.9% | 40 min | 3.12% | B− |
| Delta Air Lines (this page) | 1,342 | 77.2% | 95 min | 3.95% | B− |
| United Airlines | 2,382 | 71.4% | 75 min | 1.64% | C |
| Spirit Airlinesthin sample | 297 | 60.6% | 80 min | 6.06% | D− |
Flight by flight
Delta flight numbers on IAH to LGA
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 19 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–8am341 flights87.8%
- 8am–11am292 flights82.2%
- 11am–2pm41 flights70.0%
- 2pm–5pm357 flights69.3%
- 5pm–8pm311 flights70.6%
- 8pm–5am—
Scale runs 60% to 95%. Rows with fewer than 30 flights show a dash.
Book the early departure. Flights leaving between 5am–8am arrive on time 87.8% of the time, against 69.3% for the afternoon window. That is 19 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 2pm–5pm window is the busiest, with 357 flights scheduled in it.
Across the year
Delta on IAH to LGA through the year
December is the weak month at 62.2% on time, against 90.9% in September. 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, Friday is the strongest day at 82.9% on time and Sunday the weakest at 72.8%. 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 45% 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.
- 45%Carrier
- 29%National Airspace System
- 24%Late-arriving aircraft
- 2%Extreme weather
The largest share of delay minutes, 45%, 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 12,000 of the 28,000 delay minutes reported here. The split is drawn from 27,538 reported delay minutes.
Cancellations run at 3.95%, 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. 9.5% 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 74.5% 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 IAH to LGA
Put together: the delay figures matter less here than the 3.95% 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. 1,277 completed flights over 12 months sit behind that.
Related
Where to go next
- IAH to LGA, every carrier
- Delta on LGA to IAH, the return leg
- United Airlines on IAH to LGA71.4%
- Spirit Airlines on IAH to LGA60.6%
- Delta Air Lines network-wide record
- George Bush Intercontinental (IAH) delay statistics
- LaGuardia (LGA) 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.