WN4321
WN4321 (Southwest Airlines) is a multi-stop service on 13 routes, busiest Baltimore to Islip. Of 234 departures recorded from October 2024 to July 2026, 69.0% left on time, according to the US BTS.
- On-time departures69.0%of 234 flights
- Average delay16.2 min
- July 202630
- Cancelled3.4%
- 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 periods14 periods
| Period | Departures 2025 | Departures 2026 | Change vs last year |
|---|---|---|---|
| January | 23 | 5 | ▼ 78.3% |
| February | 24 | 13 | ▼ 45.8% |
| March | 4 | 5 | ▲ 25.0% |
| April | 6 | 1 | ▼ 83.3% |
| May | 7 | – | – |
| June | 2 | 27 | ▲ 1,250.0% |
| July | – | 30 | – |
| August | – | – | – |
| September | – | – | – |
| October | – | – | in progress |
| November | 29 | – | – |
| December | 31 | – | – |
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 periods14 periods
| Period | On time 2025 | On time 2026 | Change vs last year |
|---|---|---|---|
| January | 82.6% | 60.0% | ▼ 27.4% |
| February | 87.5% | 91.7% | ▲ 4.8% |
| March | 100.0% | 40.0% | ▼ 60.0% |
| April | 83.3% | 100.0% | ▲ 20.0% |
| May | 42.9% | – | – |
| June | 50.0% | 42.3% | ▼ 15.4% |
| July | – | 35.7% | – |
| August | – | – | – |
| September | – | – | – |
| October | – | – | in progress |
| November | 81.5% | – | – |
| December | 72.4% | – | – |
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 periods14 periods
| Period | Cancelled 2025 | Cancelled 2026 | Change vs last year |
|---|---|---|---|
| January | 0 | 0 | – |
| February | 0 | 1 | – |
| March | 0 | 0 | – |
| April | 0 | 0 | – |
| May | 0 | – | – |
| June | 0 | 1 | – |
| July | – | 2 | – |
| August | – | – | – |
| September | – | – | – |
| October | – | – | in progress |
| November | 2 | – | – |
| December | 2 | – | – |
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 96.6% 226
- Cancelled 3.4% 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
3| Routes | Distance (km) | Avg delay | On time | Departures |
|---|---|---|---|---|
| BWI ISP Baltimore/Washington International Thurgood Marshall Airport – Long Island MacArthur Airport | 353 | 38.4 min | 38.9% | 57 |
| PHX AUS Phoenix Sky Harbor International Airport – Austin Bergstrom International Airport | 1,401 | 4.3 min | 88.2% | 51 |
| SMF BUR Sacramento International Airport – Hollywood Burbank/Bob Hope Airport | 577 | 3.9 min | 86.1% | 46 |
Monthly figures
| Period | Departures | With departure delay recorded | On time | Cancelled |
|---|---|---|---|---|
| October 2024 | 20 | 20 | 80.0% | 0 |
| November 2024 | 5 | 5 | 100.0% | 0 |
| December 2024 | 2 | 2 | 50.0% | 0 |
| January 2025 | 23 | 23 | 82.6% | 0 |
| February 2025 | 24 | 24 | 87.5% | 0 |
| March 2025 | 4 | 4 | 100.0% | 0 |
| April 2025 | 6 | 6 | 83.3% | 0 |
| May 2025 | 7 | 7 | 42.9% | 0 |
| June 2025 | 2 | 2 | 50.0% | 0 |
| November 2025 | 29 | 27 | 81.5% | 2 |
| December 2025 | 31 | 29 | 72.4% | 2 |
| January 2026 | 5 | 5 | 60.0% | 0 |
| February 2026 | 13 | 12 | 91.7% | 1 |
| March 2026 | 5 | 5 | 40.0% | 0 |
| April 2026 | 1 | 1 | 100.0% | 0 |
| June 2026 | 27 | 26 | 42.3% | 1 |
| July 2026 | 30 | 28 | 35.7% | 2 |