WN4257
WN4257 (Southwest Airlines) is a multi-stop service on 16 routes, busiest Phoenix to Oakland. Of 283 departures recorded from October 2024 to July 2026, 57.5% left on time, according to the US BTS.
- On-time departures57.5%of 283 flights
- Average delay23.4 min
- July 202617▼ 43.3%vs July 2025
- Cancelled1.1%
- Legs flown under this number16
Recorded departures by month
All legs under this number combined; see the leg table.
Months without data are left blank.
The most recent periods16 periods
| Period | Departures 2025 | Departures 2026 | Change vs last year |
|---|---|---|---|
| January | 1 | 26 | ▲ 2,500.0% |
| February | 2 | 24 | ▲ 1,100.0% |
| March | 37 | 27 | ▼ 27.0% |
| April | 9 | 5 | ▼ 44.4% |
| May | – | – | – |
| June | 26 | 19 | ▼ 26.9% |
| July | 30 | 17 | ▼ 43.3% |
| August | 4 | – | – |
| September | – | – | – |
| October | 4 | – | in progress |
| November | 16 | – | – |
| December | 15 | – | – |
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 periods16 periods
| Period | On time 2025 | On time 2026 | Change vs last year |
|---|---|---|---|
| January | 0.0% | 88.5% | – |
| February | 50.0% | 37.5% | ▼ 25.0% |
| March | 44.4% | 69.2% | ▲ 55.8% |
| April | 11.1% | 60.0% | ▲ 440.1% |
| May | – | – | – |
| June | 50.0% | 42.1% | ▼ 15.8% |
| July | 53.3% | 52.9% | ▼ 0.7% |
| August | 75.0% | – | – |
| September | – | – | – |
| October | 75.0% | – | in progress |
| November | 93.3% | – | – |
| December | 93.3% | – | – |
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 periods16 periods
| Period | Cancelled 2025 | Cancelled 2026 | Change vs last year |
|---|---|---|---|
| January | 0 | 0 | – |
| February | 0 | 0 | – |
| March | 1 | 1 | 0.0% |
| April | 0 | 0 | – |
| May | – | – | – |
| June | 0 | 0 | – |
| July | 0 | 0 | – |
| August | 0 | – | – |
| September | – | – | – |
| October | 0 | – | in progress |
| November | 1 | – | – |
| 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 98.9% 280
- Cancelled 1.1% 3
Share of all recorded flights in the period, all legs. · Oct 14, 2024 → Jul 29, 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 |
|---|---|---|---|---|
| PHX OAK Phoenix Sky Harbor International Airport – Oakland San Francisco Bay Airport | 1,039 | 21.5 min | 53.3% | 60 |
| SFO DEN San Francisco International Airport – Denver International Airport | 1,553 | 16.4 min | 64.0% | 50 |
| SAN SJC San Diego International Airport – Mineta San Jose International Airport | 671 | 0.1 min | 88.2% | 35 |
Monthly figures
| Period | Departures | With departure delay recorded | On time | Cancelled |
|---|---|---|---|---|
| October 2024 | 14 | 14 | 35.7% | 0 |
| November 2024 | 3 | 3 | 100.0% | 0 |
| December 2024 | 4 | 4 | 50.0% | 0 |
| January 2025 | 1 | 1 | 0.0% | 0 |
| February 2025 | 2 | 2 | 50.0% | 0 |
| March 2025 | 37 | 36 | 44.4% | 1 |
| April 2025 | 9 | 9 | 11.1% | 0 |
| June 2025 | 26 | 26 | 50.0% | 0 |
| July 2025 | 30 | 30 | 53.3% | 0 |
| August 2025 | 4 | 4 | 75.0% | 0 |
| October 2025 | 4 | 4 | 75.0% | 0 |
| November 2025 | 16 | 15 | 93.3% | 1 |
| December 2025 | 15 | 15 | 93.3% | 0 |
| January 2026 | 26 | 26 | 88.5% | 0 |
| February 2026 | 24 | 24 | 37.5% | 0 |
| March 2026 | 27 | 26 | 69.2% | 1 |
| April 2026 | 5 | 5 | 60.0% | 0 |
| June 2026 | 19 | 19 | 42.1% | 0 |
| July 2026 | 17 | 17 | 52.9% | 0 |