WN4100
WN4100 (Southwest Airlines) is a multi-stop service on 18 routes, busiest Chicago to Memphis. Of 261 departures recorded from October 2024 to July 2026, 70.7% left on time, according to the US BTS.
- On-time departures70.7%of 261 flights
- Average delay19.7 min
- July 202631▲ 14.8%vs July 2025
- Cancelled1.9%
- Legs flown under this number18
Recorded departures by month
All legs under this number combined; see the leg table.
Months without data are left blank.
The most recent periods17 periods
| Period | Departures 2025 | Departures 2026 | Change vs last year |
|---|---|---|---|
| January | 2 | 5 | ▲ 150.0% |
| February | 2 | 4 | ▲ 100.0% |
| March | 15 | 30 | ▲ 100.0% |
| April | 4 | 6 | ▲ 50.0% |
| May | 1 | – | – |
| June | 22 | 27 | ▲ 22.7% |
| July | 27 | 31 | ▲ 14.8% |
| August | 3 | – | – |
| September | – | – | – |
| October | 30 | – | in progress |
| November | 8 | – | – |
| 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 periods17 periods
| Period | On time 2025 | On time 2026 | Change vs last year |
|---|---|---|---|
| January | 100.0% | 80.0% | ▼ 20.0% |
| February | 100.0% | 33.3% | ▼ 66.7% |
| March | 66.7% | 79.3% | ▲ 19.0% |
| April | 25.0% | 83.3% | ▲ 233.3% |
| May | 100.0% | – | – |
| June | 90.9% | 33.3% | ▼ 63.3% |
| July | 96.3% | 41.4% | ▼ 57.0% |
| August | 100.0% | – | – |
| September | – | – | – |
| October | 80.0% | – | in progress |
| November | 85.7% | – | – |
| December | 75.0% | – | – |
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 periods17 periods
| Period | Cancelled 2025 | Cancelled 2026 | Change vs last year |
|---|---|---|---|
| January | 0 | 0 | – |
| February | 0 | 1 | – |
| March | 0 | 1 | – |
| April | 0 | 0 | – |
| May | 0 | – | – |
| June | 0 | 0 | – |
| July | 0 | 2 | – |
| 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 98.1% 256
- Cancelled 1.9% 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
3| Routes | Distance (km) | Avg delay | On time | Departures |
|---|---|---|---|---|
| MDW MEM Chicago Midway International Airport – Frederick W. Smith International Airport | 774 | 50.5 min | 37.5% | 58 |
| OKC DEN OKC Will Rogers World Airport – Denver International Airport | 796 | 6.5 min | 94.2% | 52 |
| DEN STL Denver International Airport – St. Louis Lambert International Airport | 1,236 | 9.7 min | 80.7% | 31 |
Monthly figures
| Period | Departures | With departure delay recorded | On time | Cancelled |
|---|---|---|---|---|
| October 2024 | 13 | 13 | 92.3% | 0 |
| November 2024 | 3 | 3 | 66.7% | 0 |
| December 2024 | 8 | 8 | 37.5% | 0 |
| January 2025 | 2 | 2 | 100.0% | 0 |
| February 2025 | 2 | 2 | 100.0% | 0 |
| March 2025 | 15 | 15 | 66.7% | 0 |
| April 2025 | 4 | 4 | 25.0% | 0 |
| May 2025 | 1 | 1 | 100.0% | 0 |
| June 2025 | 22 | 22 | 90.9% | 0 |
| July 2025 | 27 | 27 | 96.3% | 0 |
| August 2025 | 3 | 3 | 100.0% | 0 |
| October 2025 | 30 | 30 | 80.0% | 0 |
| November 2025 | 8 | 7 | 85.7% | 1 |
| December 2025 | 20 | 20 | 75.0% | 0 |
| January 2026 | 5 | 5 | 80.0% | 0 |
| February 2026 | 4 | 3 | 33.3% | 1 |
| March 2026 | 30 | 29 | 79.3% | 1 |
| April 2026 | 6 | 6 | 83.3% | 0 |
| June 2026 | 27 | 27 | 33.3% | 0 |
| July 2026 | 31 | 29 | 41.4% | 2 |