WN4128
WN4128 (Southwest Airlines) is a multi-stop service on 32 routes, busiest Phoenix to Chicago. Of 582 departures recorded from October 2024 to July 2026, 74.1% left on time, according to the US BTS.
- On-time departures74.1%of 582 flights
- Average delay16.0 min
- July 202654▲ 86.2%vs July 2025
- Cancelled0.5%
- Legs flown under this number32
Recorded departures by month
All legs under this number combined; see the leg table.
The most recent periods19 periods
| Period | Departures 2025 | Departures 2026 | Change vs last year |
|---|---|---|---|
| January | 2 | 4 | ▲ 100.0% |
| February | 2 | 4 | ▲ 100.0% |
| March | 27 | 26 | ▼ 3.7% |
| April | 19 | 60 | ▲ 215.8% |
| May | 17 | 64 | ▲ 276.5% |
| June | 22 | 55 | ▲ 150.0% |
| July | 29 | 54 | ▲ 86.2% |
| August | 28 | – | – |
| September | 30 | – | – |
| October | 57 | – | in progress |
| November | 16 | – | – |
| December | 13 | – | – |
| Year to date (Jan–Jul) | 118 | 267 | ▲ 126.3% |
according to the US BTS · October 2024 → July 2026
On-time departures by month
On time = departure within 15 minutes of schedule. Non-cancelled flights with a recorded delay only.
The most recent periods19 periods
| Period | On time 2025 | On time 2026 | Change vs last year |
|---|---|---|---|
| January | 0.0% | 100.0% | – |
| February | 50.0% | 50.0% | 0.0% |
| March | 92.6% | 80.8% | ▼ 12.8% |
| April | 68.4% | 68.3% | ▼ 0.1% |
| May | 70.6% | 64.1% | ▼ 9.3% |
| June | 54.6% | 65.5% | ▲ 20.0% |
| July | 82.8% | 70.4% | ▼ 15.0% |
| August | 82.1% | – | – |
| September | 90.0% | – | – |
| October | 87.7% | – | in progress |
| November | 100.0% | – | – |
| December | 61.5% | – | – |
| Year-to-date average (Jan–Jul) | 59.8% | 71.3% | ▲ 19.1% |
according to the US BTS · October 2024 → July 2026
Average departure delay by month
according to the US BTS · October 2024 → July 2026
Cancelled departures by month
The most recent periods19 periods
| Period | Cancelled 2025 | Cancelled 2026 | Change vs last year |
|---|---|---|---|
| January | 0 | 0 | – |
| February | 0 | 0 | – |
| March | 0 | 0 | – |
| April | 0 | 0 | – |
| May | 0 | 0 | – |
| June | 0 | 0 | – |
| July | 0 | 0 | – |
| August | 0 | – | – |
| September | 0 | – | – |
| October | 0 | – | in progress |
| November | 3 | – | – |
| December | 0 | – | – |
| Year to date (Jan–Jul) | 0 | 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% 579
- Cancelled 0.5% 3
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
8| Routes | Distance (km) | Avg delay | On time | Departures |
|---|---|---|---|---|
| PHX MDW Phoenix Sky Harbor International Airport – Chicago Midway International Airport | 2,319 | 32.2 min | 42.1% | 57 |
| BWI PVD Baltimore/Washington International Thurgood Marshall Airport – Rhode Island T. F. Green International Airport | 526 | 5.9 min | 86.0% | 57 |
| LAX DAL Los Angeles International Airport – Dallas Love Field | 2,002 | 25.1 min | 76.0% | 50 |
| OMA STL Eppley Airfield – St. Louis Lambert International Airport | 549 | 11.9 min | 71.4% | 35 |
| DAL OKC Dallas Love Field – OKC Will Rogers World Airport | 292 | 31.1 min | 58.8% | 34 |
| SAT DEN San Antonio International Airport – Denver International Airport | 1,280 | 3.6 min | 90.9% | 33 |
| ONT BWI Ontario International Airport – Baltimore/Washington International Thurgood Marshall Airport | 3,666 | 11.9 min | 84.4% | 32 |
| HRL HOU Valley International Airport – William P. Hobby Airport | 446 | 18.8 min | 67.7% | 31 |
Monthly figures
| Period | Departures | With departure delay recorded | On time | Cancelled |
|---|---|---|---|---|
| October 2024 | 29 | 29 | 65.5% | 0 |
| November 2024 | 18 | 18 | 83.3% | 0 |
| December 2024 | 6 | 6 | 66.7% | 0 |
| January 2025 | 2 | 2 | 0.0% | 0 |
| February 2025 | 2 | 2 | 50.0% | 0 |
| March 2025 | 27 | 27 | 92.6% | 0 |
| April 2025 | 19 | 19 | 68.4% | 0 |
| May 2025 | 17 | 17 | 70.6% | 0 |
| June 2025 | 22 | 22 | 54.6% | 0 |
| July 2025 | 29 | 29 | 82.8% | 0 |
| August 2025 | 28 | 28 | 82.1% | 0 |
| September 2025 | 30 | 30 | 90.0% | 0 |
| October 2025 | 57 | 57 | 87.7% | 0 |
| November 2025 | 16 | 13 | 100.0% | 3 |
| December 2025 | 13 | 13 | 61.5% | 0 |
| January 2026 | 4 | 4 | 100.0% | 0 |
| February 2026 | 4 | 4 | 50.0% | 0 |
| March 2026 | 26 | 26 | 80.8% | 0 |
| April 2026 | 60 | 60 | 68.3% | 0 |
| May 2026 | 64 | 64 | 64.1% | 0 |
| June 2026 | 55 | 55 | 65.5% | 0 |
| July 2026 | 54 | 54 | 70.4% | 0 |