WN4378
WN4378 (Southwest Airlines) is a multi-stop service on 14 routes, busiest San Diego to Baltimore. Of 348 departures recorded from November 2024 to July 2026, 66.4% left on time, according to the US BTS.
- On-time departures66.4%of 348 flights
- Average delay16.9 min
- July 202618▼ 41.9%vs July 2025
- Cancelled0.9%
- 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 | 5 | 4 | ▼ 20.0% |
| February | 8 | 10 | ▲ 25.0% |
| March | 21 | 16 | ▼ 23.8% |
| April | 20 | 40 | ▲ 100.0% |
| May | 20 | 49 | ▲ 145.0% |
| June | 29 | 20 | ▼ 31.0% |
| July | 31 | 18 | ▼ 41.9% |
| August | 4 | – | – |
| September | – | – | – |
| October | – | – | in progress |
| November | 5 | – | – |
| December | 11 | – | – |
| Year to date (Jan–Jul) | 134 | 157 | ▲ 17.2% |
according to the US BTS · November 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 | 66.7% | 25.0% | ▼ 62.5% |
| February | 87.5% | 66.7% | ▼ 23.8% |
| March | 71.4% | 56.3% | ▼ 21.3% |
| April | 45.0% | 87.5% | ▲ 94.4% |
| May | 60.0% | 73.5% | ▲ 22.5% |
| June | 82.8% | 35.0% | ▼ 57.7% |
| July | 61.3% | 44.4% | ▼ 27.5% |
| August | 75.0% | – | – |
| September | – | – | – |
| October | – | – | in progress |
| November | 100.0% | – | – |
| December | 18.2% | – | – |
| Year-to-date average (Jan–Jul) | 67.8% | 55.5% | ▼ 18.2% |
according to the US BTS · November 2024 → July 2026
Average departure delay by month
Months without data are left blank.
according to the US BTS · November 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 | 2 | 0 | ▼ 100.0% |
| February | 0 | 1 | – |
| March | 0 | 0 | – |
| April | 0 | 0 | – |
| May | 0 | 0 | – |
| June | 0 | 0 | – |
| July | 0 | 0 | – |
| August | 0 | – | – |
| September | – | – | – |
| October | – | – | in progress |
| November | 0 | – | – |
| December | 0 | – | – |
| Year to date (Jan–Jul) | 2 | 1 | ▼ 50.0% |
according to the US BTS · November 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 99.1% 345
- Cancelled 0.9% 3
Share of all recorded flights in the period, all legs. · Nov 4, 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 |
|---|---|---|---|---|
| SAN BWI San Diego International Airport – Baltimore/Washington International Thurgood Marshall Airport | 3,686 | 10.3 min | 73.8% | 61 |
| PHL STL Philadelphia International Airport – St. Louis Lambert International Airport | 1,306 | 8.1 min | 79.6% | 51 |
| SNA PHX John Wayne Orange County International Airport – Phoenix Sky Harbor International Airport | 544 | 11.0 min | 80.0% | 50 |
| SMF SNA Sacramento International Airport – John Wayne Orange County International Airport | 650 | 4.9 min | 82.5% | 40 |
| DAL LAS Dallas Love Field – Harry Reid International Airport | 1,714 | 41.3 min | 32.4% | 34 |
| BWI SAN Baltimore/Washington International Thurgood Marshall Airport – San Diego International Airport | 3,686 | 31.7 min | 48.4% | 31 |
Monthly figures
| Period | Departures | With departure delay recorded | On time | Cancelled |
|---|---|---|---|---|
| November 2024 | 13 | 13 | 76.9% | 0 |
| December 2024 | 24 | 24 | 79.2% | 0 |
| January 2025 | 5 | 3 | 66.7% | 2 |
| February 2025 | 8 | 8 | 87.5% | 0 |
| March 2025 | 21 | 21 | 71.4% | 0 |
| April 2025 | 20 | 20 | 45.0% | 0 |
| May 2025 | 20 | 20 | 60.0% | 0 |
| June 2025 | 29 | 29 | 82.8% | 0 |
| July 2025 | 31 | 31 | 61.3% | 0 |
| August 2025 | 4 | 4 | 75.0% | 0 |
| November 2025 | 5 | 5 | 100.0% | 0 |
| December 2025 | 11 | 11 | 18.2% | 0 |
| January 2026 | 4 | 4 | 25.0% | 0 |
| February 2026 | 10 | 9 | 66.7% | 1 |
| March 2026 | 16 | 16 | 56.3% | 0 |
| April 2026 | 40 | 40 | 87.5% | 0 |
| May 2026 | 49 | 49 | 73.5% | 0 |
| June 2026 | 20 | 20 | 35.0% | 0 |
| July 2026 | 18 | 18 | 44.4% | 0 |