WN4399
WN4399 (Southwest Airlines) is a multi-stop service on 19 routes, busiest San Diego to Las Vegas. Of 375 departures recorded from October 2024 to July 2026, 76.7% left on time, according to the US BTS.
- On-time departures76.7%of 375 flights
- Average delay12.0 min
- July 202627
- Cancelled0.5%
- Legs flown under this number19
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 | 9 | 36 | ▲ 300.0% |
| February | 15 | 41 | ▲ 173.3% |
| March | 2 | 33 | ▲ 1,550.0% |
| April | 14 | 9 | ▼ 35.7% |
| May | 18 | 5 | ▼ 72.2% |
| June | 3 | 23 | ▲ 666.7% |
| July | – | 27 | – |
| August | 12 | – | – |
| September | 13 | – | – |
| October | 51 | – | in progress |
| November | 17 | – | – |
| December | 6 | – | – |
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 | 75.0% | 83.3% | ▲ 11.1% |
| February | 73.3% | 82.9% | ▲ 13.1% |
| March | 100.0% | 65.6% | ▼ 34.4% |
| April | 78.6% | 77.8% | ▼ 1.0% |
| May | 66.7% | 100.0% | ▲ 50.0% |
| June | 66.7% | 82.6% | ▲ 23.9% |
| July | – | 81.5% | – |
| August | 91.7% | – | – |
| September | 92.3% | – | – |
| October | 60.8% | – | in progress |
| November | 94.1% | – | – |
| December | 100.0% | – | – |
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 periods18 periods
| Period | Cancelled 2025 | Cancelled 2026 | Change vs last year |
|---|---|---|---|
| January | 1 | 0 | ▼ 100.0% |
| February | 0 | 0 | – |
| March | 0 | 1 | – |
| April | 0 | 0 | – |
| May | 0 | 0 | – |
| June | 0 | 0 | – |
| July | – | 0 | – |
| August | 0 | – | – |
| September | 0 | – | – |
| October | 0 | – | 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 99.5% 373
- 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
4| Routes | Distance (km) | Avg delay | On time | Departures |
|---|---|---|---|---|
| SAN LAS San Diego International Airport – Harry Reid International Airport | 417 | 11.7 min | 78.2% | 55 |
| DAL LBB Dallas Love Field – Lubbock Preston Smith International Airport | 472 | 7.5 min | 82.0% | 50 |
| BUR OAK Hollywood Burbank/Bob Hope Airport – Oakland San Francisco Bay Airport | 523 | 6.0 min | 82.1% | 40 |
| DAL MCI Dallas Love Field – Kansas City International Airport | 743 | 24.3 min | 73.5% | 34 |
Monthly figures
| Period | Departures | With departure delay recorded | On time | Cancelled |
|---|---|---|---|---|
| October 2024 | 10 | 10 | 80.0% | 0 |
| November 2024 | 17 | 17 | 76.5% | 0 |
| December 2024 | 14 | 14 | 50.0% | 0 |
| January 2025 | 9 | 8 | 75.0% | 1 |
| February 2025 | 15 | 15 | 73.3% | 0 |
| March 2025 | 2 | 2 | 100.0% | 0 |
| April 2025 | 14 | 14 | 78.6% | 0 |
| May 2025 | 18 | 18 | 66.7% | 0 |
| June 2025 | 3 | 3 | 66.7% | 0 |
| August 2025 | 12 | 12 | 91.7% | 0 |
| September 2025 | 13 | 13 | 92.3% | 0 |
| October 2025 | 51 | 51 | 60.8% | 0 |
| November 2025 | 17 | 17 | 94.1% | 0 |
| December 2025 | 6 | 6 | 100.0% | 0 |
| January 2026 | 36 | 36 | 83.3% | 0 |
| February 2026 | 41 | 41 | 82.9% | 0 |
| March 2026 | 33 | 32 | 65.6% | 1 |
| April 2026 | 9 | 9 | 77.8% | 0 |
| May 2026 | 5 | 5 | 100.0% | 0 |
| June 2026 | 23 | 23 | 82.6% | 0 |
| July 2026 | 27 | 27 | 81.5% | 0 |