WN4877
WN4877 (Southwest Airlines) is a multi-stop service on 17 routes, busiest Nashville to Chicago. Of 251 departures recorded from October 2024 to July 2026, 80.1% left on time, according to the US BTS.
- On-time departures80.1%of 251 flights
- Average delay10.3 min
- July 202630
- Cancelled2.0%
- Legs flown under this number17
Recorded departures by month
All legs under this number combined; see the leg table.
Months without data are left blank.
The most recent periods14 periods
| Period | Departures 2025 | Departures 2026 | Change vs last year |
|---|---|---|---|
| January | 25 | 6 | ▼ 76.0% |
| February | 21 | 9 | ▼ 57.1% |
| March | 26 | 2 | ▼ 92.3% |
| April | 6 | – | – |
| May | – | – | – |
| June | 1 | 27 | ▲ 2,600.0% |
| July | – | 30 | – |
| August | 4 | – | – |
| September | 4 | – | – |
| October | – | – | in progress |
| November | 9 | – | – |
| December | 20 | – | – |
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 periods14 periods
| Period | On time 2025 | On time 2026 | Change vs last year |
|---|---|---|---|
| January | 60.9% | 83.3% | ▲ 36.9% |
| February | 80.0% | 87.5% | ▲ 9.4% |
| March | 69.2% | 100.0% | ▲ 44.4% |
| April | 33.3% | – | – |
| May | – | – | – |
| June | 100.0% | 88.9% | ▼ 11.1% |
| July | – | 90.0% | – |
| August | 75.0% | – | – |
| September | 100.0% | – | – |
| October | – | – | in progress |
| November | 88.9% | – | – |
| December | 65.0% | – | – |
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 periods14 periods
| Period | Cancelled 2025 | Cancelled 2026 | Change vs last year |
|---|---|---|---|
| January | 2 | 0 | ▼ 100.0% |
| February | 1 | 1 | 0.0% |
| March | 0 | 0 | – |
| April | 0 | – | – |
| May | – | – | – |
| June | 0 | 0 | – |
| July | – | 0 | – |
| August | 0 | – | – |
| September | 0 | – | – |
| October | – | – | 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 98.0% 246
- Cancelled 2.0% 5
Share of all recorded flights in the period, all legs. · Oct 14, 2024 → Jul 31, 2026
On time, leg by leg
Departures within 15 minutes of schedule; small figure = departures recorded.
Legs flown under this number
2| Routes | Distance (km) | Avg delay | On time | Departures |
|---|---|---|---|---|
| BNA MDW Nashville International Airport – Chicago Midway International Airport | 636 | 5.6 min | 81.6% | 91 |
| SJC LAX Mineta San Jose International Airport – Los Angeles International Airport | 496 | 4.3 min | 89.5% | 57 |
Monthly figures
| Period | Departures | With departure delay recorded | On time | Cancelled |
|---|---|---|---|---|
| October 2024 | 7 | 7 | 100.0% | 0 |
| November 2024 | 26 | 25 | 92.0% | 1 |
| December 2024 | 28 | 28 | 82.1% | 0 |
| January 2025 | 25 | 23 | 60.9% | 2 |
| February 2025 | 21 | 20 | 80.0% | 1 |
| March 2025 | 26 | 26 | 69.2% | 0 |
| April 2025 | 6 | 6 | 33.3% | 0 |
| June 2025 | 1 | 1 | 100.0% | 0 |
| August 2025 | 4 | 4 | 75.0% | 0 |
| September 2025 | 4 | 4 | 100.0% | 0 |
| November 2025 | 9 | 9 | 88.9% | 0 |
| December 2025 | 20 | 20 | 65.0% | 0 |
| January 2026 | 6 | 6 | 83.3% | 0 |
| February 2026 | 9 | 8 | 87.5% | 1 |
| March 2026 | 2 | 2 | 100.0% | 0 |
| June 2026 | 27 | 27 | 88.9% | 0 |
| July 2026 | 30 | 30 | 90.0% | 0 |