WN4515
WN4515 (Southwest Airlines) is a multi-stop service on 14 routes, busiest St Louis to San Diego. Of 364 departures recorded from October 2024 to July 2026, 78.7% left on time, according to the US BTS.
- On-time departures78.7%of 364 flights
- Average delay10.2 min
- July 202630
- Cancelled0.8%
- Legs flown under this number14
Recorded departures by month
All legs under this number combined; see the leg table.
Months without data are left blank.
The most recent periods17 periods
| Period | Departures 2025 | Departures 2026 | Change vs last year |
|---|---|---|---|
| January | 8 | 12 | ▲ 50.0% |
| February | 7 | 1 | ▼ 85.7% |
| March | 26 | 16 | ▼ 38.5% |
| April | 27 | 28 | ▲ 3.7% |
| May | 26 | 31 | ▲ 19.2% |
| June | 4 | 30 | ▲ 650.0% |
| July | – | 30 | – |
| August | 18 | – | – |
| September | 21 | – | – |
| October | – | – | in progress |
| November | 19 | – | – |
| December | 17 | – | – |
according to the US BTS · October 2024 → July 2026
On-time departures by month
Months without data are left blank.
On time = departure within 15 minutes of schedule. Non-cancelled flights with a recorded delay only.
The most recent periods17 periods
| Period | On time 2025 | On time 2026 | Change vs last year |
|---|---|---|---|
| January | 87.5% | 83.3% | ▼ 4.8% |
| February | 100.0% | 100.0% | 0.0% |
| March | 88.5% | 100.0% | ▲ 13.0% |
| April | 88.9% | 89.3% | ▲ 0.4% |
| May | 100.0% | 83.9% | ▼ 16.1% |
| June | 100.0% | 56.7% | ▼ 43.3% |
| July | – | 36.7% | – |
| August | 77.8% | – | – |
| September | 76.2% | – | – |
| October | – | – | in progress |
| November | 63.2% | – | – |
| December | 64.7% | – | – |
according to the US BTS · October 2024 → July 2026
Average departure delay by month
Months without data are left blank.
according to the US BTS · October 2024 → July 2026
Cancelled departures by month
Months without data are left blank.
The most recent periods17 periods
| Period | Cancelled 2025 | Cancelled 2026 | Change vs last year |
|---|---|---|---|
| January | 0 | 0 | – |
| February | 0 | 0 | – |
| March | 0 | 1 | – |
| April | 0 | 0 | – |
| May | 1 | 0 | ▼ 100.0% |
| June | 0 | 0 | – |
| July | – | 0 | – |
| August | 0 | – | – |
| September | 0 | – | – |
| October | – | – | in progress |
| November | 0 | – | – |
| December | 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 99.2% 361
- Cancelled 0.8% 3
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
7| Routes | Distance (km) | Avg delay | On time | Departures |
|---|---|---|---|---|
| STL SAN St. Louis Lambert International Airport – San Diego International Airport | 2,501 | 6.6 min | 86.2% | 58 |
| STL AUS St. Louis Lambert International Airport – Austin Bergstrom International Airport | 1,161 | 32.5 min | 45.6% | 57 |
| LGA STL LaGuardia Airport – St. Louis Lambert International Airport | 1,426 | -0.1 min | 95.9% | 50 |
| ORD DEN Chicago O'Hare International Airport – Denver International Airport | 1,426 | 0.2 min | 94.4% | 37 |
| BNA MKE Nashville International Airport – General Mitchell International Airport | 766 | 11.9 min | 71.4% | 35 |
| SMF BWI Sacramento International Airport – Baltimore/Washington International Thurgood Marshall Airport | 3,845 | 5.2 min | 87.5% | 32 |
| BWI MCO Baltimore/Washington International Thurgood Marshall Airport – Orlando International Airport | 1,269 | 10.1 min | 75.0% | 32 |
Monthly figures
| Period | Departures | With departure delay recorded | On time | Cancelled |
|---|---|---|---|---|
| October 2024 | 16 | 16 | 87.5% | 0 |
| November 2024 | 11 | 10 | 100.0% | 1 |
| December 2024 | 16 | 16 | 75.0% | 0 |
| January 2025 | 8 | 8 | 87.5% | 0 |
| February 2025 | 7 | 7 | 100.0% | 0 |
| March 2025 | 26 | 26 | 88.5% | 0 |
| April 2025 | 27 | 27 | 88.9% | 0 |
| May 2025 | 26 | 25 | 100.0% | 1 |
| June 2025 | 4 | 4 | 100.0% | 0 |
| August 2025 | 18 | 18 | 77.8% | 0 |
| September 2025 | 21 | 21 | 76.2% | 0 |
| November 2025 | 19 | 19 | 63.2% | 0 |
| December 2025 | 17 | 17 | 64.7% | 0 |
| January 2026 | 12 | 12 | 83.3% | 0 |
| February 2026 | 1 | 1 | 100.0% | 0 |
| March 2026 | 16 | 15 | 100.0% | 1 |
| April 2026 | 28 | 28 | 89.3% | 0 |
| May 2026 | 31 | 31 | 83.9% | 0 |
| June 2026 | 30 | 30 | 56.7% | 0 |
| July 2026 | 30 | 30 | 36.7% | 0 |