Route reliability record
DEN→LGA
Denver to New York
- Flights
- 4,672
- Period
- July 2025 to June 2026
- Distance
- 1,620 mi
- Carriers
- 4
This route sits in the middle of the pack with a C. About seven flights in ten arrive on time by the DOT's definition, 6 points worse than the national rate of 77.6%. The late ones land about an hour behind schedule. That rests on 4,672 flights, of which Delta Air Lines flew 1,036 at 79.0% on time.
Delta Air Lines is the most reliable of the three carriers covered here at 79.0% on time across 1,036 flights.
Key figures
On time
71.5%
Arrivals under 15 minutes late, of 4,501 completed flights
Avg delay
68 min
Across delayed arrivals only, not all flights
Cancelled
2.74%
National rate is 1.81%
Best carrier
Delta
79.0% on time across 1,036 flights
These figures cover 4,672 flights between July 2025 and June 2026. Beyond the headline rate, 10.8% 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
Which airline is most reliable on DEN to LGA
The choice of carrier is not cosmetic here. Delta Air Lines arrives on time 79.0% of the time; Southwest Airlines manages 64.0%. 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 |
|---|---|---|---|---|---|
| Delta Air Lines | 1,036 | 79.0% | 81 min | 4.44% | B− |
| United Airlines | 2,017 | 74.0% | 69 min | 1.83% | C |
| Southwest Airlines | 1,467 | 64.0% | 60 min | 2.66% | D |
| Frontier Airlinesthin sample | 152 | 61.6% | 76 min | 3.95% | D− |
Delta Air Lines cancels 4.4% 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.
Departure window
The best time of day to leave
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 30 points, against 15 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am638 flights90.1%
- 8am–11am1,101 flights78.7%
- 11am–2pm888 flights71.9%
- 2pm–5pm1,092 flights62.8%
- 5pm–8pm953 flights60.2%
- 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: 60.2% on time, against 90.1% 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 1,101 flights scheduled in it.
Across the year
When delays peak on this route
This route's year swings by 23 points from best month to worst, which is wide. An annual average tells you very little about the week you are actually flying, so read the strip rather than the headline if your dates are fixed.
July is the worst month at 58.9% on time, 23 points below January, the best at 82.0%. 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. July was the busiest month here, with 409 flights.
Across the week, Saturday is the strongest day at 82.3% on time and Sunday the weakest at 64.8%. 18 points is a smaller lever than departure hour, but it is free.
Delay causes
Why this route gets delayed
One category carries most of the weight here. National Airspace System accounts for 44% of the 87,000 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.
- 44%National Airspace System
- 27%Carrier
- 26%Late-arriving aircraft
- 3%Extreme weather
- 0%Security
44% 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 38,000 minutes out of 87,000, against a national NAS share of 21%. The split is drawn from 86,733 reported delay minutes.
Cancellations run at 2.74%, against 1.81% nationally. That is roughly one flight in 40 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 actually costs
For anyone connecting, the number to weigh is not the on-time rate but the tail behind it. 10.8% 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.
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 runs 70.7% on time across 4,672 flights, within about a point 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 4,672 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 this route
Put together: the calendar is the biggest lever here, not the carrier or the hour. January runs 82.0% on time and July 58.9%, a swing of 23 points. If the dates move at all, move them out of July before you think about anything else. 4,501 completed flights over 12 months sit behind that.
Common questions
DEN to LGA questions
How often is DEN to LGA delayed?
Roughly one flight in four arrive at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 28.5% of the 4,672 flights in this analysis, against 22.4% nationally. Delayed flights are late by about an hour on average.
Which airline is most reliable on DEN to LGA?
Delta Air Lines leads at 79.0% on time across 1,036 flights. Southwest Airlines is at the other end on 64.0%, a gap of 15 points. Sample size matters as much as the percentage: a rate built from a few hundred flights moves around far more than one built from ten thousand.
What time of day has the fewest delays on DEN to LGA?
The 5am–8am departure window is the strongest at 90.1% on time. The 5pm–8pm window is the weakest at 60.2%, 30 points behind. Later departures inherit delays from earlier flights the same aircraft has already flown, which is why the curve slopes the way it does.
How bad are July delays on DEN to LGA?
July is the weakest month at 58.9% on time, compared with 82.0% in January. Across the year that is 23 points between the best and worst months. Moving flexible dates out of that month is one of the few things that reliably helps.
Related
Where to go next
- LGA to DEN — the return legseparate record
- Denver International (DEN) delay statistics
- LaGuardia (LGA) delay statistics
- Delta Air Lines on-time record79.0%
- United Airlines on-time record74.0%
- Southwest Airlines on-time record64.0%
- The best time of day to fly, according to 7.04 million flight records
- What a cancellation rate actually tells you (and what it hides)
Direction matters. DEN to LGA and LGA to DEN are scored separately because they are separate operations, with different departure banks and different aircraft. Compare the return leg.
Source: US DOT Bureau of Transportation Statistics, on-time performance data, July 2025 to June 2026. Updated monthly. How this data is collected.