WN4435
WN4435 (Southwest Airlines) is a multi-stop service on 13 routes, busiest San Antonio to Houston. Of 393 departures recorded from October 2024 to July 2026, 84.2% left on time, according to the US BTS.
- On-time departures84.2%of 393 flights
- Average delay6.4 min
- July 202630▼ 3.2%vs July 2025
- Cancelled1.8%
- Legs flown under this number13
Recorded departures by month
All legs under this number combined; see the leg table.
Months without data are left blank.
The most recent periods15 periods
| Period | Departures 2025 | Departures 2026 | Change vs last year |
|---|---|---|---|
| January | 25 | 6 | ▼ 76.0% |
| February | 9 | – | – |
| March | 2 | 27 | ▲ 1,250.0% |
| April | 23 | 6 | ▼ 73.9% |
| May | 31 | – | – |
| June | 30 | 27 | ▼ 10.0% |
| July | 31 | 30 | ▼ 3.2% |
| August | 4 | – | – |
| September | – | – | – |
| October | – | – | in progress |
| November | 26 | – | – |
| December | 29 | – | – |
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 periods15 periods
| Period | On time 2025 | On time 2026 | Change vs last year |
|---|---|---|---|
| January | 72.0% | 100.0% | ▲ 38.9% |
| February | 88.9% | – | – |
| March | 50.0% | 85.2% | ▲ 70.4% |
| April | 100.0% | 100.0% | 0.0% |
| May | 87.1% | – | – |
| June | 96.4% | 61.5% | ▼ 36.2% |
| July | 100.0% | 61.5% | ▼ 38.5% |
| August | 100.0% | – | – |
| September | – | – | – |
| October | – | – | in progress |
| November | 88.5% | – | – |
| December | 89.7% | – | – |
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 periods15 periods
| Period | Cancelled 2025 | Cancelled 2026 | Change vs last year |
|---|---|---|---|
| January | 0 | 0 | – |
| February | 0 | – | – |
| March | 0 | 0 | – |
| April | 0 | 0 | – |
| May | 0 | – | – |
| June | 2 | 1 | ▼ 50.0% |
| July | 0 | 4 | – |
| August | 0 | – | – |
| September | – | – | – |
| 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 98.2% 386
- Cancelled 1.8% 7
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
6| Routes | Distance (km) | Avg delay | On time | Departures |
|---|---|---|---|---|
| SAT HOU San Antonio International Airport – William P. Hobby Airport | 309 | -3.9 min | 98.3% | 61 |
| STL LGA St. Louis Lambert International Airport – LaGuardia Airport | 1,426 | 3.5 min | 91.5% | 59 |
| HNL PHX Daniel K. Inouye International Airport – Phoenix Sky Harbor International Airport | 4,689 | -0.1 min | 93.1% | 58 |
| BWI CVG Baltimore/Washington International Thurgood Marshall Airport – Cincinnati Northern Kentucky International Airport | 690 | 25.8 min | 61.5% | 57 |
| MDW BWI Chicago Midway International Airport – Baltimore/Washington International Thurgood Marshall Airport | 981 | 5.4 min | 74.3% | 35 |
| SJC BUR Mineta San Jose International Airport – Hollywood Burbank/Bob Hope Airport | 477 | -0.5 min | 87.9% | 33 |
Monthly figures
| Period | Departures | With departure delay recorded | On time | Cancelled |
|---|---|---|---|---|
| October 2024 | 20 | 20 | 80.0% | 0 |
| November 2024 | 33 | 33 | 84.9% | 0 |
| December 2024 | 34 | 34 | 76.5% | 0 |
| January 2025 | 25 | 25 | 72.0% | 0 |
| February 2025 | 9 | 9 | 88.9% | 0 |
| March 2025 | 2 | 2 | 50.0% | 0 |
| April 2025 | 23 | 23 | 100.0% | 0 |
| May 2025 | 31 | 31 | 87.1% | 0 |
| June 2025 | 30 | 28 | 96.4% | 2 |
| July 2025 | 31 | 31 | 100.0% | 0 |
| August 2025 | 4 | 4 | 100.0% | 0 |
| November 2025 | 26 | 26 | 88.5% | 0 |
| December 2025 | 29 | 29 | 89.7% | 0 |
| January 2026 | 6 | 6 | 100.0% | 0 |
| March 2026 | 27 | 27 | 85.2% | 0 |
| April 2026 | 6 | 6 | 100.0% | 0 |
| June 2026 | 27 | 26 | 61.5% | 1 |
| July 2026 | 30 | 26 | 61.5% | 4 |