WN4129
WN4129 (Southwest Airlines) is a multi-stop service on 22 routes, busiest St Louis to Tampa. Of 378 departures recorded from October 2024 to July 2026, 76.3% left on time, according to the US BTS.
- On-time departures76.3%of 378 flights
- Average delay11.1 min
- July 202626▼ 39.5%vs July 2025
- Cancelled0.5%
- Legs flown under this number22
Recorded departures by month
All legs under this number combined; see the leg table.
The most recent periods19 periods
| Period | Departures 2025 | Departures 2026 | Change vs last year |
|---|---|---|---|
| January | 5 | 4 | ▼ 20.0% |
| February | 12 | 1 | ▼ 91.7% |
| March | 28 | 27 | ▼ 3.6% |
| April | 10 | 30 | ▲ 200.0% |
| May | 6 | 30 | ▲ 400.0% |
| June | 38 | 26 | ▼ 31.6% |
| July | 43 | 26 | ▼ 39.5% |
| August | 29 | – | – |
| September | 26 | – | – |
| October | 1 | – | in progress |
| November | 5 | – | – |
| December | 12 | – | – |
| Year to date (Jan–Jul) | 142 | 144 | ▲ 1.4% |
according to the US BTS · October 2024 → July 2026
On-time departures by month
On time = departure within 15 minutes of schedule. Non-cancelled flights with a recorded delay only.
The most recent periods19 periods
| Period | On time 2025 | On time 2026 | Change vs last year |
|---|---|---|---|
| January | 100.0% | 50.0% | ▼ 50.0% |
| February | 66.7% | 100.0% | ▲ 50.0% |
| March | 75.0% | 100.0% | ▲ 33.3% |
| April | 50.0% | 66.7% | ▲ 33.3% |
| May | 50.0% | 62.1% | ▲ 24.1% |
| June | 89.2% | 38.5% | ▼ 56.9% |
| July | 90.7% | 53.9% | ▼ 40.6% |
| August | 100.0% | – | – |
| September | 92.3% | – | – |
| October | 100.0% | – | in progress |
| November | 100.0% | – | – |
| December | 58.3% | – | – |
| Year-to-date average (Jan–Jul) | 74.5% | 67.3% | ▼ 9.7% |
according to the US BTS · October 2024 → July 2026
Average departure delay by month
according to the US BTS · October 2024 → July 2026
Cancelled departures by month
The most recent periods19 periods
| Period | Cancelled 2025 | Cancelled 2026 | Change vs last year |
|---|---|---|---|
| January | 0 | 0 | – |
| February | 0 | 0 | – |
| March | 0 | 0 | – |
| April | 0 | 0 | – |
| May | 0 | 1 | – |
| June | 1 | 0 | ▼ 100.0% |
| July | 0 | 0 | – |
| August | 0 | – | – |
| September | 0 | – | – |
| October | 0 | – | in progress |
| November | 0 | – | – |
| December | 0 | – | – |
| Year to date (Jan–Jul) | 1 | 1 | 0.0% |
according to the US BTS · October 2024 → July 2026
This is a historical record of departures already flown, not a forecast for your flight.
Several legs: the headline figure averages all of them. See the leg table.
Cancellation share
- Not cancelled 99.5% 376
- Cancelled 0.5% 2
Share of all recorded flights in the period, all legs. · Oct 13, 2024 → Jul 31, 2026
On time, leg by leg
Departures within 15 minutes of schedule; small figure = departures recorded.
Legs flown under this number
6| Routes | Distance (km) | Avg delay | On time | Departures |
|---|---|---|---|---|
| STL TPA St. Louis Lambert International Airport – Tampa International Airport | 1,400 | 2.9 min | 88.5% | 61 |
| SAN SMF San Diego International Airport – Sacramento International Airport | 773 | 13.7 min | 68.0% | 50 |
| PIT HOU Pittsburgh International Airport – William P. Hobby Airport | 1,820 | 0.0 min | 96.0% | 50 |
| DAL PHX Dallas Love Field – Phoenix Sky Harbor International Airport | 1,412 | 29.0 min | 50.0% | 48 |
| ONT DEN Ontario International Airport – Denver International Airport | 1,316 | 1.8 min | 97.0% | 33 |
| DEN BOS Denver International Airport – Boston Logan International Airport | 2,816 | 16.6 min | 66.7% | 33 |
Monthly figures
| Period | Departures | With departure delay recorded | On time | Cancelled |
|---|---|---|---|---|
| October 2024 | 9 | 9 | 55.6% | 0 |
| November 2024 | 2 | 2 | 100.0% | 0 |
| December 2024 | 8 | 8 | 100.0% | 0 |
| January 2025 | 5 | 5 | 100.0% | 0 |
| February 2025 | 12 | 12 | 66.7% | 0 |
| March 2025 | 28 | 28 | 75.0% | 0 |
| April 2025 | 10 | 10 | 50.0% | 0 |
| May 2025 | 6 | 6 | 50.0% | 0 |
| June 2025 | 38 | 37 | 89.2% | 1 |
| July 2025 | 43 | 43 | 90.7% | 0 |
| August 2025 | 29 | 29 | 100.0% | 0 |
| September 2025 | 26 | 26 | 92.3% | 0 |
| October 2025 | 1 | 1 | 100.0% | 0 |
| November 2025 | 5 | 5 | 100.0% | 0 |
| December 2025 | 12 | 12 | 58.3% | 0 |
| January 2026 | 4 | 4 | 50.0% | 0 |
| February 2026 | 1 | 1 | 100.0% | 0 |
| March 2026 | 27 | 27 | 100.0% | 0 |
| April 2026 | 30 | 30 | 66.7% | 0 |
| May 2026 | 30 | 29 | 62.1% | 1 |
| June 2026 | 26 | 26 | 38.5% | 0 |
| July 2026 | 26 | 26 | 53.9% | 0 |