WN4237
WN4237 (Southwest Airlines) is a multi-stop service on 24 routes, busiest San Diego to Oakland. Of 357 departures recorded from November 2024 to July 2026, 62.9% left on time, according to the US BTS.
- On-time departures62.9%of 357 flights
- Average delay18.9 min
- July 202631▲ 287.5%vs July 2025
- Cancelled0.3%
- Legs flown under this number24
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 | 3 | 5 | ▲ 66.7% |
| February | 10 | 2 | ▼ 80.0% |
| March | 2 | 4 | ▲ 100.0% |
| April | 6 | 34 | ▲ 466.7% |
| May | 9 | 38 | ▲ 322.2% |
| June | 9 | 30 | ▲ 233.3% |
| July | 8 | 31 | ▲ 287.5% |
| August | 30 | – | – |
| September | 34 | – | – |
| October | 5 | – | in progress |
| November | 27 | – | – |
| December | 27 | – | – |
| Year to date (Jan–Jul) | 47 | 144 | ▲ 206.4% |
according to the US BTS · November 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 | 100.0% | 0.0% | ▼ 100.0% |
| February | 50.0% | 50.0% | 0.0% |
| March | 50.0% | 25.0% | ▼ 50.0% |
| April | 100.0% | 55.9% | ▼ 44.1% |
| May | 100.0% | 71.1% | ▼ 29.0% |
| June | 88.9% | 26.7% | ▼ 70.0% |
| July | 100.0% | 25.8% | ▼ 74.2% |
| August | 73.3% | – | – |
| September | 85.3% | – | – |
| October | 60.0% | – | in progress |
| November | 53.9% | – | – |
| December | 44.4% | – | – |
| Year-to-date average (Jan–Jul) | 84.1% | 36.3% | ▼ 56.8% |
according to the US BTS · November 2024 → July 2026
Average departure delay by month
according to the US BTS · November 2024 → July 2026
Cancelled departures by month
The most recent periods19 periods
| Period | Cancelled 2025 | Cancelled 2026 | Change vs last year |
|---|---|---|---|
| January | 0 | 0 | – |
| February | 0 | 0 | – |
| March | 0 | 0 | – |
| April | 0 | 0 | – |
| May | 0 | 0 | – |
| June | 0 | 0 | – |
| July | 0 | 0 | – |
| August | 0 | – | – |
| September | 0 | – | – |
| October | 0 | – | in progress |
| November | 1 | – | – |
| December | 0 | – | – |
| Year to date (Jan–Jul) | 0 | 0 |
according to the US BTS · November 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 99.7% 356
- Cancelled 0.3% 1
Share of all recorded flights in the period, all legs. · Nov 3, 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 |
|---|---|---|---|---|
| SAN OAK San Diego International Airport – Oakland San Francisco Bay Airport | 718 | 33.5 min | 45.6% | 58 |
| SAN LAS San Diego International Airport – Harry Reid International Airport | 417 | 13.0 min | 68.4% | 57 |
| SFO PHX San Francisco International Airport – Phoenix Sky Harbor International Airport | 1,047 | 43.3 min | 12.0% | 50 |
| LAS RNO Harry Reid International Airport – Reno Tahoe International Airport | 556 | 9.8 min | 81.1% | 37 |
Monthly figures
| Period | Departures | With departure delay recorded | On time | Cancelled |
|---|---|---|---|---|
| November 2024 | 23 | 23 | 91.3% | 0 |
| December 2024 | 20 | 20 | 95.0% | 0 |
| January 2025 | 3 | 3 | 100.0% | 0 |
| February 2025 | 10 | 10 | 50.0% | 0 |
| March 2025 | 2 | 2 | 50.0% | 0 |
| April 2025 | 6 | 6 | 100.0% | 0 |
| May 2025 | 9 | 9 | 100.0% | 0 |
| June 2025 | 9 | 9 | 88.9% | 0 |
| July 2025 | 8 | 8 | 100.0% | 0 |
| August 2025 | 30 | 30 | 73.3% | 0 |
| September 2025 | 34 | 34 | 85.3% | 0 |
| October 2025 | 5 | 5 | 60.0% | 0 |
| November 2025 | 27 | 26 | 53.9% | 1 |
| December 2025 | 27 | 27 | 44.4% | 0 |
| January 2026 | 5 | 5 | 0.0% | 0 |
| February 2026 | 2 | 2 | 50.0% | 0 |
| March 2026 | 4 | 4 | 25.0% | 0 |
| April 2026 | 34 | 34 | 55.9% | 0 |
| May 2026 | 38 | 38 | 71.1% | 0 |
| June 2026 | 30 | 30 | 26.7% | 0 |
| July 2026 | 31 | 31 | 25.8% | 0 |