WN4219
WN4219 (Southwest Airlines) is a multi-stop service on 26 routes, busiest San Francisco to St Louis. Of 351 departures recorded from October 2024 to July 2026, 58.5% left on time, according to the US BTS.
- On-time departures58.5%of 351 flights
- Average delay25.6 min
- July 202625▲ 212.5%vs July 2025
- Cancelled0.6%
- Legs flown under this number26
Recorded departures by month
All legs under this number combined; see the leg table.
Months without data are left blank.
The most recent periods18 periods
| Period | Departures 2025 | Departures 2026 | Change vs last year |
|---|---|---|---|
| January | 1 | 2 | ▲ 100.0% |
| February | 2 | 2 | 0.0% |
| March | 23 | – | – |
| April | 32 | 21 | ▼ 34.4% |
| May | 35 | 26 | ▼ 25.7% |
| June | 12 | 27 | ▲ 125.0% |
| July | 8 | 25 | ▲ 212.5% |
| August | 13 | – | – |
| September | 13 | – | – |
| October | 43 | – | in progress |
| November | 28 | – | – |
| December | 21 | – | – |
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 periods18 periods
| Period | On time 2025 | On time 2026 | Change vs last year |
|---|---|---|---|
| January | 100.0% | 100.0% | 0.0% |
| February | 100.0% | 0.0% | ▼ 100.0% |
| March | 60.9% | – | – |
| April | 65.6% | 9.5% | ▼ 85.5% |
| May | 42.9% | 3.9% | ▼ 91.0% |
| June | 83.3% | 59.3% | ▼ 28.9% |
| July | 37.5% | 68.0% | ▲ 81.3% |
| August | 69.2% | – | – |
| September | 76.9% | – | – |
| October | 62.8% | – | in progress |
| November | 76.9% | – | – |
| December | 90.5% | – | – |
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 periods18 periods
| Period | Cancelled 2025 | Cancelled 2026 | Change vs last year |
|---|---|---|---|
| January | 0 | 0 | – |
| February | 0 | 0 | – |
| March | 0 | – | – |
| April | 0 | 0 | – |
| May | 0 | 0 | – |
| June | 0 | 0 | – |
| July | 0 | 0 | – |
| August | 0 | – | – |
| September | 0 | – | – |
| October | 0 | – | in progress |
| November | 2 | – | – |
| 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 99.4% 349
- Cancelled 0.6% 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
5| Routes | Distance (km) | Avg delay | On time | Departures |
|---|---|---|---|---|
| SFO STL San Francisco International Airport – St. Louis Lambert International Airport | 2,786 | 69.9 min | 6.0% | 50 |
| SAN DEN San Diego International Airport – Denver International Airport | 1,371 | 5.5 min | 83.7% | 45 |
| MDW GRR Chicago Midway International Airport – Gerald R. Ford International Airport | 220 | 35.5 min | 59.5% | 42 |
| DEN BZN Denver International Airport – Bozeman Yellowstone International Airport | 844 | 19.8 min | 52.9% | 34 |
| SLC PHX Salt Lake City International Airport – Phoenix Sky Harbor International Airport | 818 | 21.3 min | 76.7% | 30 |
Monthly figures
| Period | Departures | With departure delay recorded | On time | Cancelled |
|---|---|---|---|---|
| October 2024 | 11 | 11 | 81.8% | 0 |
| November 2024 | 3 | 3 | 100.0% | 0 |
| December 2024 | 3 | 3 | 100.0% | 0 |
| January 2025 | 1 | 1 | 100.0% | 0 |
| February 2025 | 2 | 2 | 100.0% | 0 |
| March 2025 | 23 | 23 | 60.9% | 0 |
| April 2025 | 32 | 32 | 65.6% | 0 |
| May 2025 | 35 | 35 | 42.9% | 0 |
| June 2025 | 12 | 12 | 83.3% | 0 |
| July 2025 | 8 | 8 | 37.5% | 0 |
| August 2025 | 13 | 13 | 69.2% | 0 |
| September 2025 | 13 | 13 | 76.9% | 0 |
| October 2025 | 43 | 43 | 62.8% | 0 |
| November 2025 | 28 | 26 | 76.9% | 2 |
| December 2025 | 21 | 21 | 90.5% | 0 |
| January 2026 | 2 | 2 | 100.0% | 0 |
| February 2026 | 2 | 2 | 0.0% | 0 |
| April 2026 | 21 | 21 | 9.5% | 0 |
| May 2026 | 26 | 26 | 3.9% | 0 |
| June 2026 | 27 | 27 | 59.3% | 0 |
| July 2026 | 25 | 25 | 68.0% | 0 |