Carrier route record
DLLGA→DEN
Delta Air Lines · New York to Denver
- Flights
- 1,033
- Period
- September 2025 to August 2026
- Share of route
- 22%
- Carriers
- 4
Historical statistics for September 2025 to August 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: 4.5% of scheduled flights never operate, against 1.9% 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 1,033 flights. The strongest carrier on the route with a full sample, United Airlines, flew 2,021 at 77.6% on time.
The national on-time rate over the same period is 77.3%, so Delta on LGA to DEN runs 7 points behind the country as a whole. Across a thousand flights that is about 66 extra late arrivals.
Key figures
On time
70.7%
Arrivals under 15 minutes late, of 974 completed flights
Avg delay
68 min
Across delayed arrivals only, not all flights
Cancelled
4.55%
National rate is 1.89%
Whole route
70.0%
Every carrier on LGA to DEN, 4,663 flights
These figures cover 1,033 flights between September 2025 and August 2026. Beyond the headline rate, 11.3% of arrivals land a full hour or more behind schedule, against 8.3% nationally.
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Carrier by carrier
Delta against every carrier on LGA to DEN
Delta flew 1,033 of the 4,663 flights on LGA to DEN, about 22% of it. Its 70.7% on time is about level with the route as a whole at 70.0%. Ranked by on-time rate it is number two of four carriers on the route, where the range runs from United at 77.6% to Southwest at 59.3%. 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 77.6% of the time; Southwest Airlines manages 59.3%. Sample sizes sit next to every figure, because a two-point gap across 1,516 flights means less than a ten-point one.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| United Airlines | 2,021 | 77.6% | 80 min | 2.08% | B |
| Delta Air Lines (this page) | 1,033 | 70.7% | 68 min | 4.55% | C− |
| Frontier Airlinesthin sample | 93 | 67.8% | 121 min | 3.23% | C− |
| Southwest Airlines | 1,516 | 59.3% | 63 min | 4.02% | D− |
Southwest Airlines cancels 4.0% 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
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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 18 points between the best and worst carrier.
- 5am–8am315 flights82.5%
- 8am–11am49 flights77.1%
- 11am–2pm4 flights—
- 2pm–5pm350 flights70.2%
- 5pm–8pm315 flights58.2%
- 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: 58.2% on time, against 82.5% 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 350 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 80.2% on time and Thursday the weakest at 65.0%, a spread of 15 points.
Arrival by arrival
How late Delta on LGA to DEN runs when it is late
Delta on LGA to DEN often beats the schedule: 297 of 974 completed flights, 30%, arrived 15 minutes or more early. The 285 late arrivals split 107 under half an hour, 68 between 30 and 60 minutes, and 110 an hour or more.
- 15+ min early297 flights30.5%
- Within 15 min392 flights40.2%
- 15–29 min late107 flights11.0%
- 30–59 min late68 flights7.0%
- 1–2 hours late68 flights7.0%
- 2+ hours late42 flights4.3%
Scale runs 0% to 100%.
Share of 974 completed flights by arrival against schedule.
Time lost at the gate mostly stays lost. Of 196 departures that left 15 minutes late or more, only 21 made it up before arrival. In the other direction, 110 flights left on time yet arrived 15 minutes late or more, so that delay built up after pushback: in the air, in a holding pattern or on the ground at DEN.
The worst days
Worst days for Delta on LGA to DEN
The latest arrival of the period was on 25 November 2025, 6 hours 44 minutes behind schedule; most of its delay minutes were filed as carrier-caused (crew, maintenance, fuelling, baggage). The five worst days are spread across November, June, December, July and May, with no single month standing out.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 25 November 2025 | 6 hours 44 minutes | Carrier |
| 14 June 2026 | 5 hours 42 minutes | Carrier |
| 23 December 2025 | 5 hours 9 minutes | Late-arriving aircraft |
| 15 July 2026 | 4 hours 57 minutes | National Airspace System |
| 20 May 2026 | 4 hours 43 minutes | Late-arriving aircraft |
Delay causes
Why Delta runs late on this route
Carriers report a reason for every delay minute they cause, in five DOT categories. The split below is by minutes, not by number of flights, so a handful of very long weather delays weighs as much as many short ones. It covers 19,000 reported delay minutes.
- 38%Carrier
- 37%National Airspace System
- 24%Late-arriving aircraft
- 1%Extreme weather
37% of delay minutes are charged to the National Airspace System: air traffic volume, runway configuration, ground stops. No carrier can price its way out of that, which is why airport choice moves the number here more than carrier choice does. That is 7,069 minutes out of 19,000, against a national NAS share of 21%. The split is drawn from 19,315 reported delay minutes.
The largest share of delay minutes, 38%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. It accounts for 7,432 of the 19,000 delay minutes reported here.
Cancellations run at 4.55%, against 1.89% nationally. That is roughly one flight in twenty 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
11.3% of arrivals land a full hour or more behind schedule, against 8.3% nationally. Ninety minutes is the honest minimum for a connection 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 79.7% on time across 1,033 flights, 9 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 9 points of difference.
One caution: this is a thin sample. 1,033 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 4.55% cancellation rate. A late arrival costs you about 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. 974 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 DEN77.6%
- Southwest Airlines on LGA to DEN59.3%
- 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, September 2025 to August 2026. Last updated ; recomputed monthly. How this data is collected.