WN4020
WN4020 (Southwest Airlines) is a multi-stop service on 28 routes, busiest Denver to Richmond. Of 418 departures recorded from October 2024 to July 2026, 62.9% left on time, according to the US BTS.
- On-time departures62.9%of 418 flights
- Average delay20.0 min
- July 202621▼ 32.3%vs July 2025
- Cancelled0.7%
- Legs flown under this number28
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 | 5 | 2 | ▼ 60.0% |
| February | 17 | 14 | ▼ 17.6% |
| March | 29 | 28 | ▼ 3.4% |
| April | 7 | 70 | ▲ 900.0% |
| May | 1 | 81 | ▲ 8,000.0% |
| June | 26 | 27 | ▲ 3.8% |
| July | 31 | 21 | ▼ 32.3% |
| August | 4 | – | – |
| September | – | – | – |
| October | 21 | – | in progress |
| November | 2 | – | – |
| December | 3 | – | – |
| Year to date (Jan–Jul) | 116 | 243 | ▲ 109.5% |
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 | 60.0% | 50.0% | ▼ 16.7% |
| February | 82.4% | 100.0% | ▲ 21.4% |
| March | 75.0% | 59.3% | ▼ 21.0% |
| April | 28.6% | 65.7% | ▲ 130.0% |
| May | 0.0% | 75.0% | – |
| June | 50.0% | 44.4% | ▼ 11.1% |
| July | 35.5% | 38.1% | ▲ 7.4% |
| August | 50.0% | – | – |
| September | – | – | – |
| October | 57.1% | – | in progress |
| November | 100.0% | – | – |
| December | 66.7% | – | – |
| Year-to-date average (Jan–Jul) | 47.3% | 61.8% | ▲ 30.5% |
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 | 0 | – |
| March | 1 | 1 | 0.0% |
| April | 0 | 0 | – |
| May | 0 | 1 | – |
| June | 0 | 0 | – |
| July | 0 | 0 | – |
| August | 0 | – | – |
| September | – | – | – |
| October | 0 | – | in progress |
| November | 0 | – | – |
| December | 0 | – | – |
| Year to date (Jan–Jul) | 1 | 2 | ▲ 100.0% |
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 99.3% 415
- Cancelled 0.7% 3
Share of all recorded flights in the period, all legs. · Oct 13, 2024 → Jul 31, 2026
On time, leg by leg
Departures within 15 minutes of schedule; small figure = departures recorded.
Legs flown under this number
6| Routes | Distance (km) | Avg delay | On time | Departures |
|---|---|---|---|---|
| DEN RIC Denver International Airport – Richmond International Airport | 2,379 | 46.2 min | 42.6% | 61 |
| RNO LAS Reno Tahoe International Airport – Harry Reid International Airport | 556 | 4.7 min | 88.4% | 43 |
| TPA DEN Tampa International Airport – Denver International Airport | 2,423 | 33.7 min | 34.2% | 41 |
| MHT MCO Manchester-Boston Regional Airport – Orlando International Airport | 1,840 | 12.0 min | 65.6% | 33 |
| LAS DEN Harry Reid International Airport – Denver International Airport | 1,009 | 3.7 min | 87.5% | 33 |
| HOU CMH William P. Hobby Airport – John Glenn Columbus International Airport | 1,610 | 24.6 min | 63.6% | 33 |
Monthly figures
| Period | Departures | With departure delay recorded | On time | Cancelled |
|---|---|---|---|---|
| October 2024 | 27 | 27 | 74.1% | 0 |
| November 2024 | 2 | 2 | 100.0% | 0 |
| January 2025 | 5 | 5 | 60.0% | 0 |
| February 2025 | 17 | 17 | 82.4% | 0 |
| March 2025 | 29 | 28 | 75.0% | 1 |
| April 2025 | 7 | 7 | 28.6% | 0 |
| May 2025 | 1 | 1 | 0.0% | 0 |
| June 2025 | 26 | 26 | 50.0% | 0 |
| July 2025 | 31 | 31 | 35.5% | 0 |
| August 2025 | 4 | 4 | 50.0% | 0 |
| October 2025 | 21 | 21 | 57.1% | 0 |
| November 2025 | 2 | 2 | 100.0% | 0 |
| December 2025 | 3 | 3 | 66.7% | 0 |
| January 2026 | 2 | 2 | 50.0% | 0 |
| February 2026 | 14 | 14 | 100.0% | 0 |
| March 2026 | 28 | 27 | 59.3% | 1 |
| April 2026 | 70 | 70 | 65.7% | 0 |
| May 2026 | 81 | 80 | 75.0% | 1 |
| June 2026 | 27 | 27 | 44.4% | 0 |
| July 2026 | 21 | 21 | 38.1% | 0 |