WN255
WN255 (Southwest Airlines) is a multi-stop service on 44 routes, busiest St Louis to Washington. Of 772 departures recorded from October 2024 to July 2026, 66.7% left on time, according to the US BTS.
- On-time departures66.7%of 772 flights
- Average delay17.9 min
- July 202659▲ 73.5%vs July 2025
- Cancelled1.2%
- Legs flown under this number44
Recorded departures by month
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 | 28 | 48 | ▲ 71.4% |
| February | 28 | 37 | ▲ 32.1% |
| March | 32 | 32 | 0.0% |
| April | 33 | 27 | ▼ 18.2% |
| May | 36 | 31 | ▼ 13.9% |
| June | 34 | 54 | ▲ 58.8% |
| July | 34 | 59 | ▲ 73.5% |
| August | 32 | – | – |
| September | 30 | – | – |
| October | 32 | – | in progress |
| November | 32 | – | – |
| December | 31 | – | – |
| Year to date (Jan–Jul) | 225 | 288 | ▲ 28.0% |
according to the US BTS · October 2024 → July 2026
On-time departures by month
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 | 84.0% | 64.6% | ▼ 23.1% |
| February | 50.0% | 54.1% | ▲ 8.1% |
| March | 87.1% | 31.0% | ▼ 64.4% |
| April | 78.1% | 88.9% | ▲ 13.8% |
| May | 72.2% | 96.8% | ▲ 34.0% |
| June | 50.0% | 38.9% | ▼ 22.2% |
| July | 45.5% | 32.2% | ▼ 29.2% |
| August | 87.5% | – | – |
| September | 93.3% | – | – |
| October | 87.5% | – | in progress |
| November | 62.5% | – | – |
| December | 80.7% | – | – |
| Year-to-date average (Jan–Jul) | 66.7% | 58.1% | ▼ 13.0% |
according to the US BTS · October 2024 → July 2026
Average departure delay by month
according to the US BTS · October 2024 → July 2026
Cancelled departures by month
The most recent periods19 periods
| Period | Cancelled 2025 | Cancelled 2026 | Change vs last year |
|---|---|---|---|
| January | 3 | 0 | ▼ 100.0% |
| February | 0 | 0 | – |
| March | 1 | 3 | ▲ 200.0% |
| April | 1 | 0 | ▼ 100.0% |
| May | 0 | 0 | – |
| June | 0 | 0 | – |
| July | 1 | 0 | ▼ 100.0% |
| August | 0 | – | – |
| September | 0 | – | – |
| October | 0 | – | in progress |
| November | 0 | – | – |
| December | 0 | – | – |
| Year to date (Jan–Jul) | 6 | 3 | ▼ 50.0% |
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 98.8% 763
- Cancelled 1.2% 9
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 |
|---|---|---|---|---|
| STL DCA St. Louis Lambert International Airport – Ronald Reagan Washington National Airport | 1,154 | 13.0 min | 73.0% | 92 |
| MDW BUF Chicago Midway International Airport – Buffalo Niagara International Airport | 752 | 25.3 min | 47.5% | 60 |
| STL TPA St. Louis Lambert International Airport – Tampa International Airport | 1,400 | 1.3 min | 94.8% | 58 |
| MIA BWI Miami International Airport – Baltimore/Washington International Thurgood Marshall Airport | 1,526 | -0.3 min | 96.6% | 58 |
| FLL BNA Fort Lauderdale Hollywood International Airport – Nashville International Airport | 1,278 | 22.1 min | 83.9% | 33 |
| AUS ECP Austin Bergstrom International Airport – Northwest Florida Beaches International Airport | 1,139 | 3.7 min | 84.4% | 32 |
Monthly figures
| Period | Departures | With departure delay recorded | On time | Cancelled |
|---|---|---|---|---|
| October 2024 | 38 | 38 | 68.4% | 0 |
| November 2024 | 33 | 33 | 97.0% | 0 |
| December 2024 | 31 | 31 | 74.2% | 0 |
| January 2025 | 28 | 25 | 84.0% | 3 |
| February 2025 | 28 | 28 | 50.0% | 0 |
| March 2025 | 32 | 31 | 87.1% | 1 |
| April 2025 | 33 | 32 | 78.1% | 1 |
| May 2025 | 36 | 36 | 72.2% | 0 |
| June 2025 | 34 | 34 | 50.0% | 0 |
| July 2025 | 34 | 33 | 45.5% | 1 |
| August 2025 | 32 | 32 | 87.5% | 0 |
| September 2025 | 30 | 30 | 93.3% | 0 |
| October 2025 | 32 | 32 | 87.5% | 0 |
| November 2025 | 32 | 32 | 62.5% | 0 |
| December 2025 | 31 | 31 | 80.7% | 0 |
| January 2026 | 48 | 48 | 64.6% | 0 |
| February 2026 | 37 | 37 | 54.1% | 0 |
| March 2026 | 32 | 29 | 31.0% | 3 |
| April 2026 | 27 | 27 | 88.9% | 0 |
| May 2026 | 31 | 31 | 96.8% | 0 |
| June 2026 | 54 | 54 | 38.9% | 0 |
| July 2026 | 59 | 59 | 32.2% | 0 |