WN4035
WN4035 (Southwest Airlines) is a multi-stop service on 21 routes, busiest Philadelphia to Denver. Of 379 departures recorded from October 2024 to July 2026, 72.2% left on time, according to the US BTS.
- On-time departures72.2%of 379 flights
- Average delay15.6 min
- July 202626▲ 116.7%vs July 2025
- Cancelled0.5%
- Legs flown under this number21
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 | 10 | 19 | ▲ 90.0% |
| February | 5 | 38 | ▲ 660.0% |
| March | 6 | 4 | ▼ 33.3% |
| April | 18 | 21 | ▲ 16.7% |
| May | 23 | 25 | ▲ 8.7% |
| June | 15 | 28 | ▲ 86.7% |
| July | 12 | 26 | ▲ 116.7% |
| August | 2 | – | – |
| September | – | – | – |
| October | 30 | – | in progress |
| November | 26 | – | – |
| December | 29 | – | – |
| Year to date (Jan–Jul) | 89 | 161 | ▲ 80.9% |
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 | 66.7% | 84.2% | ▲ 26.3% |
| February | 60.0% | 68.4% | ▲ 14.0% |
| March | 33.3% | 100.0% | ▲ 200.0% |
| April | 50.0% | 71.4% | ▲ 42.9% |
| May | 56.5% | 72.0% | ▲ 27.4% |
| June | 53.3% | 50.0% | ▼ 6.2% |
| July | 58.3% | 64.0% | ▲ 9.7% |
| August | 100.0% | – | – |
| September | – | – | – |
| October | 96.7% | – | in progress |
| November | 96.2% | – | – |
| December | 96.6% | – | – |
| Year-to-date average (Jan–Jul) | 54.0% | 72.9% | ▲ 34.9% |
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 | 1 | 0 | ▼ 100.0% |
| February | 0 | 0 | – |
| March | 0 | 0 | – |
| April | 0 | 0 | – |
| May | 0 | 0 | – |
| June | 0 | 0 | – |
| July | 0 | 1 | – |
| August | 0 | – | – |
| September | – | – | – |
| October | 0 | – | in progress |
| November | 0 | – | – |
| December | 0 | – | – |
| Year to date (Jan–Jul) | 1 | 1 | 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% 377
- Cancelled 0.5% 2
Share of all recorded flights in the period, all legs. · Oct 15, 2024 → Jul 31, 2026
On time, leg by leg
Departures within 15 minutes of schedule; small figure = departures recorded.
Legs flown under this number
4| Routes | Distance (km) | Avg delay | On time | Departures |
|---|---|---|---|---|
| PHL DEN Philadelphia International Airport – Denver International Airport | 2,501 | 3.1 min | 93.3% | 60 |
| TPA MDW Tampa International Airport – Chicago Midway International Airport | 1,607 | 24.8 min | 56.3% | 49 |
| RSW BWI Southwest Florida International Airport – Baltimore/Washington International Thurgood Marshall Airport | 1,483 | 9.6 min | 69.1% | 42 |
| DEN HOU Denver International Airport – William P. Hobby Airport | 1,422 | 41.9 min | 50.0% | 42 |
Monthly figures
| Period | Departures | With departure delay recorded | On time | Cancelled |
|---|---|---|---|---|
| October 2024 | 6 | 6 | 100.0% | 0 |
| November 2024 | 12 | 12 | 66.7% | 0 |
| December 2024 | 24 | 24 | 70.8% | 0 |
| January 2025 | 10 | 9 | 66.7% | 1 |
| February 2025 | 5 | 5 | 60.0% | 0 |
| March 2025 | 6 | 6 | 33.3% | 0 |
| April 2025 | 18 | 18 | 50.0% | 0 |
| May 2025 | 23 | 23 | 56.5% | 0 |
| June 2025 | 15 | 15 | 53.3% | 0 |
| July 2025 | 12 | 12 | 58.3% | 0 |
| August 2025 | 2 | 2 | 100.0% | 0 |
| October 2025 | 30 | 30 | 96.7% | 0 |
| November 2025 | 26 | 26 | 96.2% | 0 |
| December 2025 | 29 | 29 | 96.6% | 0 |
| January 2026 | 19 | 19 | 84.2% | 0 |
| February 2026 | 38 | 38 | 68.4% | 0 |
| March 2026 | 4 | 4 | 100.0% | 0 |
| April 2026 | 21 | 21 | 71.4% | 0 |
| May 2026 | 25 | 25 | 72.0% | 0 |
| June 2026 | 28 | 28 | 50.0% | 0 |
| July 2026 | 26 | 25 | 64.0% | 1 |