Carrier route record
WNLGA→DEN
Southwest Airlines · New York to Denver
- Flights
- 1,516
- Period
- September 2025 to August 2026
- Share of route
- 33%
- Carriers
- 4
Historical statistics for September 2025 to August 2026, not live status. For today’s flights, check with Southwest Airlines.
Southwest on LGA to DEN carries a cancellation problem, not just a delay problem: 4.0% of scheduled flights never operate, against 1.9% nationally. Of the ones that do fly, a little over half of flights arrive on time, worth a D− overall. The punctuality figure counts only flights that actually departed, so it flatters an operation that cancels this often. That rests on 1,516 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 Southwest on LGA to DEN runs 18 points behind the country as a whole. Across a thousand flights that is about 180 extra late arrivals.
Key figures
On time
59.3%
Arrivals under 15 minutes late, of 1,443 completed flights
Avg delay
63 min
Across delayed arrivals only, not all flights
Cancelled
4.02%
National rate is 1.89%
Whole route
70.0%
Every carrier on LGA to DEN, 4,663 flights
These figures cover 1,516 flights between September 2025 and August 2026. Beyond the headline rate, 13.7% of arrivals land a full hour or more behind schedule, against 8.3% nationally.
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Carrier by carrier
Southwest against every carrier on LGA to DEN
Southwest flew 1,516 of the 4,663 flights on LGA to DEN, about 33% of it. Its 59.3% on time is 11 points worse than the route as a whole, which runs 70.0%. Ranked by on-time rate it is last 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; Delta Air Lines manages 70.7%. Sample sizes sit next to every figure, because a two-point gap across 1,033 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 | 1,033 | 70.7% | 68 min | 4.55% | C− |
| Frontier Airlinesthin sample | 93 | 67.8% | 121 min | 3.23% | C− |
| Southwest Airlines (this page) | 1,516 | 59.3% | 63 min | 4.02% | D− |
Delta Air Lines cancels 4.5% 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.
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Departure window
When Southwest runs best on this route
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 45 points, against 7 points between the best and worst carrier.
- 5am–8am345 flights85.5%
- 8am–11am206 flights61.0%
- 11am–2pm151 flights62.1%
- 2pm–5pm435 flights50.2%
- 5pm–8pm190 flights40.7%
- 8pm–5am189 flights44.1%
Scale runs 30% to 90%.
The 5pm–8pm window is where this operation falls apart: 40.7% on time, against 85.5% 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 435 flights scheduled in it.
Across the year
Southwest on LGA to DEN through the year
August is the worst month at 40.9% on time, 37 points below January, the best at 77.5%. 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 146 flights.
Across the week, Saturday is the strongest day at 66.7% on time and Monday the weakest at 49.3%, a spread of 17 points.
Arrival by arrival
How late Southwest on LGA to DEN runs when it is late
The 587 late arrivals split 184 under half an hour, 205 between 30 and 60 minutes, and 198 an hour or more.
- 15+ min early240 flights16.6%
- Within 15 min616 flights42.7%
- 15–29 min late184 flights12.8%
- 30–59 min late205 flights14.2%
- 1–2 hours late124 flights8.6%
- 2+ hours late74 flights5.1%
Scale runs 0% to 100%.
Share of 1,443 completed flights by arrival against schedule.
159 of 640 late departures made up the time and arrived on time, 25% of them. In the other direction, 106 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 Southwest on LGA to DEN
The latest arrival of the period was on 12 March 2026, 7 hours 15 minutes behind schedule; most of its delay minutes were filed as a late-arriving aircraft. The same cause led on three of the five worst days.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 12 March 2026 | 7 hours 15 minutes | Late-arriving aircraft |
| 10 August 2026 | 7 hours 12 minutes | National Airspace System |
| 14 December 2025 | 5 hours 45 minutes | Late-arriving aircraft |
| 23 June 2026 | 5 hours 43 minutes | National Airspace System |
| 19 December 2025 | 5 hours 2 minutes | Late-arriving aircraft |
Delay causes
Why Southwest runs late on this route
Late-arriving aircraft accounts for 49% of the 37,000 delay minutes carriers reported here, and the remaining four split what is left.
- 49%Late-arriving aircraft
- 26%National Airspace System
- 23%Carrier
- 2%Extreme weather
- 0%Security
49% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 37,000 reported delay minutes here, that single category outweighs weather by 22 to one. The split is drawn from 36,958 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 85.5% on time here.
Cancellations run at 4.02%, against 1.89% 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
13.7% 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 63.0% on time across 1,517 flights, 4 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 4 points of difference.
The sample behind these figures is 1,516 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 Southwest on LGA to DEN
Put together: the delay figures matter less here than the 4.02% 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. 1,443 completed flights over 12 months sit behind that.
Related
Where to go next
- LGA to DEN, every carrier
- Southwest on DEN to LGA, the return leg
- United Airlines on LGA to DEN77.6%
- Delta Air Lines on LGA to DEN70.7%
- Southwest Airlines network-wide record
- LaGuardia (LGA) delay statistics
- Denver International (DEN) delay statistics
- The US routes with the most cancellations
- Why the first flight of the morning is statistically safest
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.