WN4127
WN4127 (Southwest Airlines) is a multi-stop service on 25 routes, busiest San Diego to Sacramento. Of 365 departures recorded from October 2024 to July 2026, 68.1% left on time, according to the US BTS.
- On-time departures68.1%of 365 flights
- Average delay20.0 min
- July 202651▲ 410.0%vs July 2025
- Cancelled1.1%
- Legs flown under this number25
Recorded departures by month
All legs under this number combined; see the leg table.
Months without data are left blank.
The most recent periods15 periods
| Period | Departures 2025 | Departures 2026 | Change vs last year |
|---|---|---|---|
| January | 3 | 5 | ▲ 66.7% |
| February | – | 4 | – |
| March | 12 | 20 | ▲ 66.7% |
| April | 18 | 26 | ▲ 44.4% |
| May | 23 | 27 | ▲ 17.4% |
| June | 8 | 50 | ▲ 525.0% |
| July | 10 | 51 | ▲ 410.0% |
| August | – | – | – |
| September | – | – | – |
| October | – | – | in progress |
| November | 29 | – | – |
| December | 31 | – | – |
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 periods15 periods
| Period | On time 2025 | On time 2026 | Change vs last year |
|---|---|---|---|
| January | 100.0% | 80.0% | ▼ 20.0% |
| February | – | 100.0% | – |
| March | 83.3% | 90.0% | ▲ 8.0% |
| April | 66.7% | 92.3% | ▲ 38.5% |
| May | 61.9% | 81.5% | ▲ 31.6% |
| June | 50.0% | 46.0% | ▼ 8.0% |
| July | 30.0% | 38.0% | ▲ 26.7% |
| August | – | – | – |
| September | – | – | – |
| October | – | – | in progress |
| November | 75.0% | – | – |
| December | 71.0% | – | – |
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 periods15 periods
| Period | Cancelled 2025 | Cancelled 2026 | Change vs last year |
|---|---|---|---|
| January | 0 | 0 | – |
| February | – | 0 | – |
| March | 0 | 0 | – |
| April | 0 | 0 | – |
| May | 2 | 0 | ▼ 100.0% |
| June | 0 | 0 | – |
| July | 0 | 1 | – |
| August | – | – | – |
| September | – | – | – |
| October | – | – | 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% 361
- Cancelled 1.1% 4
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
5| Routes | Distance (km) | Avg delay | On time | Departures |
|---|---|---|---|---|
| SAN SMF San Diego International Airport – Sacramento International Airport | 773 | 4.9 min | 88.0% | 50 |
| MEM DAL Frederick W. Smith International Airport – Dallas Love Field | 679 | 34.2 min | 54.2% | 49 |
| PHX SLC Phoenix Sky Harbor International Airport – Salt Lake City International Airport | 818 | 16.0 min | 69.6% | 46 |
| HOU MAF William P. Hobby Airport – Midland International Air and Space Port | 709 | 16.7 min | 68.4% | 40 |
| DAL AMA Dallas Love Field – Rick Husband Amarillo International Airport | 520 | 44.3 min | 26.5% | 34 |
Monthly figures
| Period | Departures | With departure delay recorded | On time | Cancelled |
|---|---|---|---|---|
| October 2024 | 19 | 19 | 94.7% | 0 |
| November 2024 | 18 | 18 | 83.3% | 0 |
| December 2024 | 11 | 11 | 100.0% | 0 |
| January 2025 | 3 | 3 | 100.0% | 0 |
| March 2025 | 12 | 12 | 83.3% | 0 |
| April 2025 | 18 | 18 | 66.7% | 0 |
| May 2025 | 23 | 21 | 61.9% | 2 |
| June 2025 | 8 | 8 | 50.0% | 0 |
| July 2025 | 10 | 10 | 30.0% | 0 |
| November 2025 | 29 | 28 | 75.0% | 1 |
| December 2025 | 31 | 31 | 71.0% | 0 |
| January 2026 | 5 | 5 | 80.0% | 0 |
| February 2026 | 4 | 4 | 100.0% | 0 |
| March 2026 | 20 | 20 | 90.0% | 0 |
| April 2026 | 26 | 26 | 92.3% | 0 |
| May 2026 | 27 | 27 | 81.5% | 0 |
| June 2026 | 50 | 50 | 46.0% | 0 |
| July 2026 | 51 | 50 | 38.0% | 1 |