Route reliability record
LGA→DEN
New York to Denver
- 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, 7 points worse than the national rate of 77.6%. The late ones land a little over an hour behind schedule. That rests on 4,672 flights, of which United Airlines flew 2,017 at 77.8% on time.
United Airlines is the most reliable of the three carriers covered here at 77.8% on time across 2,017 flights.
Key figures
On time
70.7%
Arrivals under 15 minutes late, of 4,503 completed flights
Avg delay
69 min
Across delayed arrivals only, not all flights
Cancelled
2.93%
National rate is 1.81%
Best carrier
United
77.8% on time across 2,017 flights
These figures cover 4,672 flights between July 2025 and June 2026. Beyond the headline rate, 10.3% 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 LGA to DEN
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 | 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− |
Delta Air Lines cancels 4.2% 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 31 points, against 17 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am1,015 flights86.1%
- 8am–11am499 flights80.9%
- 11am–2pm565 flights79.7%
- 2pm–5pm1,128 flights63.8%
- 5pm–8pm1,123 flights58.6%
- 8pm–5am342 flights55.5%
Scale runs 45% to 90%. Rows with fewer than 30 flights show a dash.
The 8pm–5am window is where this operation falls apart: 55.5% on time, against 86.1% 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 2pm–5pm window is the busiest, with 1,128 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.
June is the worst month at 59.9% on time, 23 points below January, the best at 82.6%. 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 78.5% on time and Sunday the weakest at 66.2%. 12 points is a smaller lever than departure hour, but it is free.
Delay causes
Why this route gets delayed
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 91,000 reported delay minutes.
- 40%Late-arriving aircraft
- 28%National Airspace System
- 27%Carrier
- 5%Extreme weather
- 0%Security
40% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. That is a cascade, and cascades start small and grow through the day. Across 91,000 reported delay minutes here, that single category outweighs weather by 9 to one. It is the strongest argument for booking the first departure of the morning, when the aircraft has been sitting at the gate overnight with nothing to inherit. The split is drawn from 91,152 reported delay minutes.
The practical consequence: the 5am–8am departure is the one that starts clean. Its aircraft has no earlier leg to be late from, which is exactly why that window shows 86.1% on time here.
Cancellations run at 2.93%, against 1.81% nationally. That is roughly one flight in 30 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. 10.3% 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 71.5% 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 delay figures matter less here than the 2.93% 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. 4,503 completed flights over 12 months sit behind that.
Common questions
LGA to DEN questions
How often is LGA to DEN delayed?
Roughly one flight in three arrive at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 29.3% of the 4,672 flights in this analysis, against 22.4% nationally. Delayed flights are late by a little over an hour on average.
Which airline is most reliable on LGA to DEN?
United Airlines leads at 77.8% on time across 2,017 flights. Southwest Airlines is at the other end on 61.1%, a gap of 17 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 LGA to DEN?
The 5am–8am departure window is the strongest at 86.1% on time. The 8pm–5am window is the weakest at 55.5%, 31 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 June delays on LGA to DEN?
June is the weakest month at 59.9% on time, compared with 82.6% 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
- DEN to LGA — the return legseparate record
- LaGuardia (LGA) delay statistics
- Denver International (DEN) delay statistics
- United Airlines on-time record77.8%
- Delta Air Lines on-time record71.3%
- Frontier Airlines on-time record64.4%
- Why the first flight of the morning is statistically safest
- The best time of day to fly, according to 7.04 million flight records
Direction matters. LGA to DEN and DEN to LGA 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.