WN4479
WN4479 (Southwest Airlines) is a multi-stop service on 19 routes, busiest Washington to Chicago. Of 334 departures recorded from October 2024 to July 2026, 65.1% left on time, according to the US BTS.
- On-time departures65.1%of 334 flights
- Average delay17.7 min
- July 202634▲ 161.5%vs July 2025
- Cancelled3.0%
- 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 | 17 | 3 | ▼ 82.4% |
| February | 9 | – | – |
| March | 2 | 31 | ▲ 1,450.0% |
| April | 12 | 10 | ▼ 16.7% |
| May | 18 | 4 | ▼ 77.8% |
| June | 14 | 31 | ▲ 121.4% |
| July | 13 | 34 | ▲ 161.5% |
| August | 21 | – | – |
| September | 21 | – | – |
| October | 43 | – | in progress |
| November | 7 | – | – |
| December | 11 | – | – |
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 | 88.2% | 100.0% | ▲ 13.3% |
| February | 88.9% | – | – |
| March | 100.0% | 71.0% | ▼ 29.0% |
| April | 75.0% | 60.0% | ▼ 20.0% |
| May | 77.8% | 75.0% | ▼ 3.6% |
| June | 57.1% | 53.6% | ▼ 6.2% |
| July | 46.2% | 42.9% | ▼ 7.1% |
| August | 57.1% | – | – |
| September | 71.4% | – | – |
| October | 39.5% | – | in progress |
| November | 71.4% | – | – |
| 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 | 0 | 0 | – |
| February | 0 | – | – |
| March | 0 | 0 | – |
| April | 0 | 0 | – |
| May | 0 | 0 | – |
| June | 0 | 3 | – |
| July | 0 | 6 | – |
| 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 97.0% 324
- Cancelled 3.0% 10
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 |
|---|---|---|---|---|
| DCA MDW Ronald Reagan Washington National Airport – Chicago Midway International Airport | 964 | 37.7 min | 50.0% | 57 |
| LAS SNA Harry Reid International Airport – John Wayne Orange County International Airport | 365 | 3.7 min | 79.6% | 50 |
| SMF SAN Sacramento International Airport – San Diego International Airport | 773 | 18.6 min | 62.5% | 40 |
| SMF DEN Sacramento International Airport – Denver International Airport | 1,460 | 17.0 min | 63.6% | 33 |
| OAK SEA Oakland San Francisco Bay Airport – Seattle–Tacoma International Airport | 1,082 | 24.5 min | 48.4% | 31 |
Monthly figures
| Period | Departures | With departure delay recorded | On time | Cancelled |
|---|---|---|---|---|
| October 2024 | 13 | 13 | 84.6% | 0 |
| November 2024 | 14 | 14 | 85.7% | 0 |
| December 2024 | 6 | 5 | 100.0% | 1 |
| January 2025 | 17 | 17 | 88.2% | 0 |
| February 2025 | 9 | 9 | 88.9% | 0 |
| March 2025 | 2 | 2 | 100.0% | 0 |
| April 2025 | 12 | 12 | 75.0% | 0 |
| May 2025 | 18 | 18 | 77.8% | 0 |
| June 2025 | 14 | 14 | 57.1% | 0 |
| July 2025 | 13 | 13 | 46.2% | 0 |
| August 2025 | 21 | 21 | 57.1% | 0 |
| September 2025 | 21 | 21 | 71.4% | 0 |
| October 2025 | 43 | 43 | 39.5% | 0 |
| November 2025 | 7 | 7 | 71.4% | 0 |
| December 2025 | 11 | 11 | 100.0% | 0 |
| January 2026 | 3 | 3 | 100.0% | 0 |
| March 2026 | 31 | 31 | 71.0% | 0 |
| April 2026 | 10 | 10 | 60.0% | 0 |
| May 2026 | 4 | 4 | 75.0% | 0 |
| June 2026 | 31 | 28 | 53.6% | 3 |
| July 2026 | 34 | 28 | 42.9% | 6 |