Carrier route record
DLLGA→DEN
Delta Air Lines · New York to Denver
- Flights
- 1,036
- Period
- July 2025 to June 2026
- Share of route
- 22%
- 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 DEN carries a cancellation problem, not just a delay problem: 4.2% of scheduled flights never operate, against 1.8% nationally. Of the ones that do fly, about seven flights in ten 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 1,036 flights. The strongest carrier on the route with a full sample, United Airlines, flew 2,017 at 77.8% on time.
The national on-time rate over the same period is 77.6%, so Delta on LGA to DEN runs 6 points behind the country as a whole. Across a thousand flights that is about 63 extra late arrivals.
Key figures
On time
71.3%
Arrivals under 15 minutes late, of 975 completed flights
Avg delay
71 min
Across delayed arrivals only, not all flights
Cancelled
4.15%
National rate is 1.81%
Whole route
70.7%
Every carrier on LGA to DEN, 4,672 flights
These figures cover 1,036 flights between July 2025 and June 2026. Beyond the headline rate, 10.5% 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 LGA to DEN
Delta flew 1,036 of the 4,672 flights on LGA to DEN, about 22% of it. Its 71.3% on time is about level with the route as a whole at 70.7%. Ranked by on-time rate it is number two of four carriers on the route, where the range runs from United at 77.8% to Southwest at 61.1%. 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 77.8% of the time; Southwest Airlines manages 61.1%. Sample sizes sit next to every figure, because a two-point gap across 1,467 flights means less than a ten-point one.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| United Airlines | 2,017 | 77.8% | 71 min | 1.98% | B |
| Delta Air Lines (this page) | 1,036 | 71.3% | 71 min | 4.15% | C− |
| Frontier Airlinesthin sample | 152 | 64.4% | 105 min | 3.95% | D− |
| Southwest Airlines | 1,467 | 61.1% | 63 min | 3.27% | D− |
Southwest Airlines cancels 3.3% 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.
Flight by flight
Delta flight numbers on LGA to DEN
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 24 points, against 17 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am344 flights83.7%
- 8am–11am20 flights—
- 11am–2pm5 flights—
- 2pm–5pm356 flights67.9%
- 5pm–8pm311 flights59.7%
- 8pm–5am—
Scale runs 50% to 90%. Rows with fewer than 30 flights show a dash.
The 5pm–8pm window is where this operation falls apart: 59.7% on time, against 83.7% 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 2pm–5pm window is the busiest, with 356 flights scheduled in it.
Across the year
Delta on LGA to DEN through the year
June is the worst month at 51.2% on time, 35 points below April, the best at 86.0%. 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 89 flights.
Across the week, Saturday is the strongest day at 79.4% on time and Tuesday the weakest at 66.7%. 13 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 20,000 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
- 30%National Airspace System
- 24%Late-arriving aircraft
- 1%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 8,908 of the 20,000 delay minutes reported here. The split is drawn from 19,743 reported delay minutes.
Cancellations run at 4.15%, 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. 10.5% 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.
At 1,620 miles this is transcontinental flying, and long routes get a quiet structural advantage. Scheduled block time on a flight this length carries more padding in absolute minutes, so a twenty-minute late departure often still becomes an on-time arrival. Read the on-time rate here as slightly flattering next to a short-haul route with the same operational quality.
The return leg is a different operation and performs like one: it runs 79.0% on time across 1,036 flights, 8 points above 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 8 points of difference.
One caution: this is a thin sample. 1,036 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 LGA to DEN
Put together: the delay figures matter less here than the 4.15% cancellation rate. A late arrival costs you a little over an hour; 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. 975 completed flights over 12 months sit behind that.
Related
Where to go next
- LGA to DEN, every carrier
- Delta on DEN to LGA, the return leg
- United Airlines on LGA to DEN77.8%
- Frontier Airlines on LGA to DEN64.4%
- Southwest Airlines on LGA to DEN61.1%
- Delta Air Lines network-wide record
- LaGuardia (LGA) delay statistics
- Denver International (DEN) delay statistics
- The US routes with the most cancellations
- Same route, different airline: where the carrier you pick matters most
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.