Carrier route record
WNLGA→STL
Southwest Airlines · New York to St. Louis
- 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 LGA to STL carries a cancellation problem, not just a delay problem: 3.8% of scheduled flights never operate, against 1.9% nationally. Of the ones that do fly, close to three flights in four 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 1,395 flights, with a median arrival 4 minutes early.
The national on-time rate over the same period is 77.3%, so Southwest on LGA to STL runs 4 points behind the country as a whole. Across a thousand flights that is about 40 extra late arrivals.
Key figures
On time
73.3%
Arrivals under 15 minutes late, of 1,339 completed flights
Avg delay
68 min
Across delayed arrivals only, not all flights
Cancelled
3.80%
National rate is 1.89%
Whole route
75.2%
Every carrier on LGA to STL, 2,577 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 LGA to STL
Southwest flew 1,395 of the 2,577 flights on LGA to STL, most of the route. Its 73.3% on time is 2 points worse than the route as a whole, which runs 75.2%. Ranked by on-time rate it is number two of three carriers on the route, where the range runs from Republic at 77.5% to SkyWest at 71.4%. 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 | 1,175 | 77.5% | 75 min | 5.62% | B− |
| Southwest Airlines (this page) | 1,395 | 73.3% | 68 min | 3.80% | C− |
| SkyWest Airlinesthin sample | 7 | 71.4% | 22 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 41 points, against half a point between the best and worst carrier.
- 5am–8am233 flights94.7%
- 8am–11am321 flights82.7%
- 11am–2pm168 flights77.8%
- 2pm–5pm367 flights65.1%
- 5pm–8pm305 flights53.6%
- 8pm–5am1 flights—
Scale runs 45% to 100%. Rows with fewer than 30 flights show a dash.
The 5pm–8pm window is where this operation falls apart: 53.6% on time, against 94.7% 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 367 flights scheduled in it.
Across the year
Southwest on LGA to STL through the year
August is the worst month at 59.1% on time, 28 points below January, the best at 86.7%. 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 123 flights.
Across the week, Wednesday is the strongest day at 78.3% on time and Sunday the weakest at 67.8%, a spread of 11 points.
Arrival by arrival
How late Southwest on LGA to STL runs when it is late
Southwest on LGA to STL often beats the schedule: 357 of 1,339 completed flights, 27%, arrived 15 minutes or more early. The 357 late arrivals split 122 under half an hour, 116 between 30 and 60 minutes, and 119 an hour or more.
- 15+ min early357 flights26.7%
- Within 15 min625 flights46.7%
- 15–29 min late122 flights9.1%
- 30–59 min late116 flights8.7%
- 1–2 hours late69 flights5.2%
- 2+ hours late50 flights3.7%
Scale runs 0% to 100%.
Share of 1,339 completed flights by arrival against schedule.
A late pushback is often recovered here: of 463 departures that left 15 minutes late or more, 161 still arrived on time. 55 flights left on time and still arrived late.
The worst days
Worst days for Southwest on LGA to STL
The latest arrival of the period was on 10 August 2026, 9 hours 3 minutes behind schedule; most of its delay minutes were filed as national airspace system delay. The five worst days are spread across August, July, June, October and May, with no single month standing out.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 10 August 2026 | 9 hours 3 minutes | National Airspace System |
| 18 July 2026 | 8 hours 36 minutes | National Airspace System |
| 12 June 2026 | 8 hours 30 minutes | Carrier |
| 30 October 2025 | 8 hours 16 minutes | Extreme weather |
| 18 May 2026 | 7 hours 22 minutes | Late-arriving aircraft |
Delay causes
Why Southwest runs late on this route
Late-arriving aircraft accounts for 50% of the 24,000 delay minutes carriers reported here, and the remaining four split what is left.
- 50%Late-arriving aircraft
- 23%National Airspace System
- 23%Carrier
- 5%Extreme weather
- 0%Security
50% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 24,000 reported delay minutes here, that single category outweighs weather by 11 to one. The split is drawn from 24,274 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 94.7% on time here.
Cancellations run at 3.80%, 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
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 a little over 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 69.2% on time across 1,395 flights, 4 points below 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 LGA to STL
Put together: the delay figures matter less here than the 3.80% 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. 1,339 completed flights over 12 months sit behind that.
Related
Where to go next
- LGA to STL, every carrier
- Southwest on STL to LGA, the return leg
- Republic Airways on LGA to STL77.5%
- Southwest Airlines network-wide record
- LaGuardia (LGA) delay statistics
- St. Louis Lambert International (STL) 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.