WN4351
WN4351 (Southwest Airlines) is a multi-stop service on 18 routes, busiest Chicago to Philadelphia. Of 304 departures recorded from October 2024 to July 2026, 72.0% left on time, according to the US BTS.
- On-time departures72.0%of 304 flights
- Average delay19.9 min
- July 202630▲ 500.0%vs July 2025
- Cancelled0.3%
- Legs flown under this number18
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 | 21 | 5 | ▼ 76.2% |
| February | 17 | 4 | ▼ 76.5% |
| March | 11 | – | – |
| April | 2 | 3 | ▲ 50.0% |
| May | 2 | 8 | ▲ 300.0% |
| June | 4 | 27 | ▲ 575.0% |
| July | 5 | 30 | ▲ 500.0% |
| August | 19 | – | – |
| September | 21 | – | – |
| October | – | – | in progress |
| November | 26 | – | – |
| December | 29 | – | – |
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 | 71.4% | 80.0% | ▲ 12.0% |
| February | 76.5% | 100.0% | ▲ 30.8% |
| March | 81.8% | – | – |
| April | 100.0% | 33.3% | ▼ 66.7% |
| May | 50.0% | 62.5% | ▲ 25.0% |
| June | 100.0% | 70.4% | ▼ 29.6% |
| July | 100.0% | 51.7% | ▼ 48.3% |
| August | 94.7% | – | – |
| September | 100.0% | – | – |
| October | – | – | in progress |
| November | 69.2% | – | – |
| December | 69.0% | – | – |
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 | – | – |
| April | 0 | 0 | – |
| May | 0 | 0 | – |
| June | 0 | 0 | – |
| July | 0 | 1 | – |
| 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 99.7% 303
- Cancelled 0.3% 1
Share of all recorded flights in the period, all legs. · Oct 12, 2024 → Jul 31, 2026
On time, leg by leg
Departures within 15 minutes of schedule; small figure = departures recorded.
Legs flown under this number
3| Routes | Distance (km) | Avg delay | On time | Departures |
|---|---|---|---|---|
| MDW PHL Chicago Midway International Airport – Philadelphia International Airport | 1,073 | 28.1 min | 67.4% | 139 |
| SLC PHX Salt Lake City International Airport – Phoenix Sky Harbor International Airport | 818 | 18.3 min | 70.9% | 55 |
| SMF SNA Sacramento International Airport – John Wayne Orange County International Airport | 650 | -2.9 min | 97.4% | 39 |
Monthly figures
| Period | Departures | With departure delay recorded | On time | Cancelled |
|---|---|---|---|---|
| October 2024 | 26 | 26 | 42.3% | 0 |
| November 2024 | 26 | 26 | 84.6% | 0 |
| December 2024 | 18 | 18 | 61.1% | 0 |
| January 2025 | 21 | 21 | 71.4% | 0 |
| February 2025 | 17 | 17 | 76.5% | 0 |
| March 2025 | 11 | 11 | 81.8% | 0 |
| April 2025 | 2 | 2 | 100.0% | 0 |
| May 2025 | 2 | 2 | 50.0% | 0 |
| June 2025 | 4 | 4 | 100.0% | 0 |
| July 2025 | 5 | 5 | 100.0% | 0 |
| August 2025 | 19 | 19 | 94.7% | 0 |
| September 2025 | 21 | 21 | 100.0% | 0 |
| November 2025 | 26 | 26 | 69.2% | 0 |
| December 2025 | 29 | 29 | 69.0% | 0 |
| January 2026 | 5 | 5 | 80.0% | 0 |
| February 2026 | 4 | 4 | 100.0% | 0 |
| April 2026 | 3 | 3 | 33.3% | 0 |
| May 2026 | 8 | 8 | 62.5% | 0 |
| June 2026 | 27 | 27 | 70.4% | 0 |
| July 2026 | 30 | 29 | 51.7% | 1 |