WN504
WN504 (Southwest Airlines) is a multi-stop service on 36 routes, busiest Washington to Houston. Of 747 departures recorded from October 2024 to July 2026, 77.0% left on time, according to the US BTS.
- On-time departures77.0%of 747 flights
- Average delay12.5 min
- July 202631▲ 55.0%vs July 2025
- Cancelled1.1%
- Legs flown under this number36
according to the US BTS · Oct 12, 2024 → Jul 31, 2026 domestic flights only
Recorded departures by month
Partial coverage: domestic flights only · 22 of 22 periods have data
All legs under this number combined; see the leg table.
The most recent periods19 periods
| Period | Departures 2025 | Departures 2026 | Change vs last year |
|---|---|---|---|
| January | 35 | 33 | ▼ 5.7% |
| February | 44 | 28 | ▼ 36.4% |
| March | 33 | 46 | ▲ 39.4% |
| April | 35 | 9 | ▼ 74.3% |
| May | 35 | 1 | ▼ 97.1% |
| June | 25 | 27 | ▲ 8.0% |
| July | 20 | 31 | ▲ 55.0% |
| August | 39 | – | – |
| September | 39 | – | – |
| October | 39 | – | in progress |
| November | 50 | – | – |
| December | 63 | – | – |
| Year to date (Jan–Jul) | 227 | 175 | ▼ 22.9% |
according to the US BTS · October 2024 → July 2026
On-time departures by month
Partial coverage: domestic flights only · 22 of 22 periods have data
On time = departure within 15 minutes of schedule. Non-cancelled flights with a recorded delay only.
The most recent periods19 periods
| Period | On time 2025 | On time 2026 | Change vs last year |
|---|---|---|---|
| January | 80.0% | 97.0% | ▲ 21.2% |
| February | 70.5% | 64.3% | ▼ 8.7% |
| March | 84.9% | 87.0% | ▲ 2.5% |
| April | 80.0% | 100.0% | ▲ 25.0% |
| May | 97.1% | 100.0% | ▲ 2.9% |
| June | 45.8% | 22.2% | ▼ 51.5% |
| July | 50.0% | 12.9% | ▼ 74.2% |
| August | 74.4% | – | – |
| September | 87.2% | – | – |
| October | 87.2% | – | in progress |
| November | 82.0% | – | – |
| December | 86.9% | – | – |
| Year-to-date average (Jan–Jul) | 72.6% | 69.0% | ▼ 4.9% |
according to the US BTS · October 2024 → July 2026
Average departure delay by month
Partial coverage: domestic flights only · 22 of 22 periods have data
according to the US BTS · October 2024 → July 2026
Cancelled departures by month
Partial coverage: domestic flights only · 22 of 22 periods have data
The most recent periods19 periods
| Period | Cancelled 2025 | Cancelled 2026 | Change vs last year |
|---|---|---|---|
| January | 5 | 0 | ▼ 100.0% |
| February | 0 | 0 | – |
| March | 0 | 0 | – |
| April | 0 | 0 | – |
| May | 0 | 0 | – |
| June | 1 | 0 | ▼ 100.0% |
| July | 0 | 0 | – |
| August | 0 | – | – |
| September | 0 | – | – |
| October | 0 | – | in progress |
| November | 0 | – | – |
| December | 2 | – | – |
| Year to date (Jan–Jul) | 6 | 0 | ▼ 100.0% |
according to the US BTS · October 2024 → July 2026
This is not a forecast
This is a historical record of departures already flown, not a forecast for your flight.
This number flies several legs
Several legs: the headline figure averages all of them. See the leg table.
Cancellation share
- Not cancelled 98.9% 739
- Cancelled 1.1% 8
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
88 of 8
| Routes | Distance (km) | Avg delay | On time | Departures |
|---|---|---|---|---|
| DCA HOU Ronald Reagan Washington National Airport – William P. Hobby Airport | 1,959 | 5.9 min | 87.5% | 91 |
| AUS BWI Austin Bergstrom International Airport – Baltimore/Washington International Thurgood Marshall Airport | 2,156 | 17.1 min | 73.1% | 68 |
| BNA DEN Nashville International Airport – Denver International Airport | 1,628 | 56.9 min | 15.8% | 57 |
| SMF SLC Sacramento International Airport – Salt Lake City International Airport | 854 | 5.2 min | 84.0% | 50 |
| RNO LAS Reno Tahoe International Airport – Harry Reid International Airport | 556 | 4.5 min | 85.1% | 47 |
| SMF ONT Sacramento International Airport – Ontario International Airport | 627 | 1.9 min | 94.7% | 38 |
| SJC DAL Mineta San Jose International Airport – Dallas Love Field | 2,329 | 2.2 min | 93.9% | 33 |
| HOU ABQ William P. Hobby Airport – Albuquerque International Sunport | 1,221 | 19.0 min | 78.8% | 33 |
Monthly figures
| Period | Departures | With departure delay recorded | On time | Cancelled |
|---|---|---|---|---|
| October 2024 | 20 | 20 | 75.0% | 0 |
| November 2024 | 40 | 40 | 95.0% | 0 |
| December 2024 | 55 | 55 | 89.1% | 0 |
| January 2025 | 35 | 30 | 80.0% | 5 |
| February 2025 | 44 | 44 | 70.5% | 0 |
| March 2025 | 33 | 33 | 84.9% | 0 |
| April 2025 | 35 | 35 | 80.0% | 0 |
| May 2025 | 35 | 35 | 97.1% | 0 |
| June 2025 | 25 | 24 | 45.8% | 1 |
| July 2025 | 20 | 20 | 50.0% | 0 |
| August 2025 | 39 | 39 | 74.4% | 0 |
| September 2025 | 39 | 39 | 87.2% | 0 |
| October 2025 | 39 | 39 | 87.2% | 0 |
| November 2025 | 50 | 50 | 82.0% | 0 |
| December 2025 | 63 | 61 | 86.9% | 2 |
| January 2026 | 33 | 33 | 97.0% | 0 |
| February 2026 | 28 | 28 | 64.3% | 0 |
| March 2026 | 46 | 46 | 87.0% | 0 |
| April 2026 | 9 | 9 | 100.0% | 0 |
| May 2026 | 1 | 1 | 100.0% | 0 |
| June 2026 | 27 | 27 | 22.2% | 0 |
| July 2026 | 31 | 31 | 12.9% | 0 |