Carrier route record
WNSTL→LGA
Southwest Airlines · St. Louis to New York
- Flights
- 1,395
- Period
- September 2025 to August 2026
- Share of route
- 54%
- Carriers
- 3
Historical statistics for September 2025 to August 2026, not live status. For today’s flights, check with Southwest Airlines.
Southwest on STL to LGA sits in the middle of the pack with a C−. About seven flights in ten arrive on time by the DOT's definition, 8 points worse than the national rate of 77.3%. The late ones land about an hour behind schedule. That rests on 1,395 flights, with a median arrival right on schedule.
The national on-time rate over the same period is 77.3%, so Southwest on STL to LGA runs 8 points behind the country as a whole. Across a thousand flights that is about 81 extra late arrivals.
Key figures
On time
69.2%
Arrivals under 15 minutes late, of 1,332 completed flights
Avg delay
57 min
Across delayed arrivals only, not all flights
Cancelled
3.08%
National rate is 1.89%
Whole route
74.0%
Every carrier on STL to LGA, 2,578 flights
These figures cover 1,395 flights between September 2025 and August 2026. Beyond the headline rate, 8.9% 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 STL to LGA
Southwest flew 1,395 of the 2,578 flights on STL to LGA, most of the route. Its 69.2% on time is 5 points worse than the route as a whole, which runs 74.0%. Ranked by on-time rate it is number two of three carriers on the route, where the range runs from Republic at 79.6% to SkyWest at 66.7%. One of those carriers flew fewer than 365 flights here, so treat their positions as rough.
Only one carrier clears this site's 365-flight floor here, so there is no comparison to draw. The table below is the full picture.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| Republic Airways | 1,176 | 79.6% | 87 min | 4.76% | B− |
| Southwest Airlines (this page) | 1,395 | 69.2% | 57 min | 3.08% | C− |
| SkyWest Airlinesthin sample | 7 | 66.7% | 26 min | 0.00% | C+ |
Timetable by Aviasales, a Travelpayouts partner. Booking through it may earn this site a commission at no cost to you; it changes no figure here.
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 40 points, against half a point between the best and worst carrier.
- 5am–8am339 flights92.4%
- 8am–11am110 flights79.8%
- 11am–2pm281 flights67.5%
- 2pm–5pm247 flights61.4%
- 5pm–8pm186 flights54.2%
- 8pm–5am232 flights52.4%
Scale runs 45% to 100%.
The 8pm–5am window is where this operation falls apart: 52.4% on time, against 92.4% 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 5am–8am window is the busiest, with 339 flights scheduled in it.
Across the year
Southwest on STL to LGA through the year
Delays peak in March, when the on-time rate falls to 57.7%. January is the strongest month at 84.1%. Moving a flexible trip across that boundary buys 26 points. July was the busiest month here, with 123 flights.
Across the week, Wednesday is the strongest day at 78.8% on time and Sunday the weakest at 60.9%, a spread of 18 points.
Arrival by arrival
How late Southwest on STL to LGA runs when it is late
The 410 late arrivals split 163 under half an hour, 128 between 30 and 60 minutes, and 119 an hour or more.
- 15+ min early233 flights17.5%
- Within 15 min689 flights51.7%
- 15–29 min late163 flights12.2%
- 30–59 min late128 flights9.6%
- 1–2 hours late76 flights5.7%
- 2+ hours late43 flights3.2%
Scale runs 0% to 100%.
Share of 1,332 completed flights by arrival against schedule.
92 of 445 late departures made up the time and arrived on time, 21% of them. 57 flights left on time and still arrived late.
The worst days
Worst days for Southwest on STL to LGA
The latest arrival of the period was on 18 May 2026, 8 hours 51 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 |
|---|---|---|
| 18 May 2026 | 8 hours 51 minutes | Late-arriving aircraft |
| 1 December 2025 | 6 hours 12 minutes | Late-arriving aircraft |
| 5 July 2026 | 5 hours 39 minutes | National Airspace System |
| 29 March 2026 | 5 hours 7 minutes | National Airspace System |
| 16 March 2026 | 4 hours 44 minutes | Late-arriving aircraft |
Delay causes
Why Southwest 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 23,000 reported delay minutes.
- 38%National Airspace System
- 33%Late-arriving aircraft
- 24%Carrier
- 4%Extreme weather
- 1%Security
38% 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 8,948 minutes out of 23,000, against a national NAS share of 21%. The split is drawn from 23,315 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 92.4% on time here.
Cancellations run at 3.08%, against 1.89% 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 costs
8.9% of arrivals land an hour or more late, close to the national 8.3%, so a 60 to 75 minute layover is reasonable here while anything under 45 minutes is a bet. Most delays on this route last about an hour, which a normal layover absorbs.
The 888 miles between these two airports put this in the middle of the US network, around two and a half to three hours of block time. That is enough cruise to absorb a ten-minute late pushback and not enough to absorb thirty.
The return leg is a different operation and performs like one: it runs 73.3% on time across 1,395 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 1,395 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 STL to LGA
Put together: the delay figures matter less here than the 3.08% 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. 1,332 completed flights over 12 months sit behind that.
Related
Where to go next
- STL to LGA, every carrier
- Southwest on LGA to STL, the return leg
- Republic Airways on STL to LGA79.6%
- Southwest Airlines network-wide record
- St. Louis Lambert International (STL) delay statistics
- LaGuardia (LGA) 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.