WN4331
WN4331 (Southwest Airlines) is a multi-stop service on 27 routes, busiest San Diego to San Jose. Of 592 departures recorded from October 2024 to July 2026, 78.6% left on time, according to the US BTS.
- On-time departures78.6%of 592 flights
- Average delay10.1 min
- July 202627▲ 237.5%vs July 2025
- Cancelled1.4%
- Legs flown under this number27
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 | 25 | 38 | ▲ 52.0% |
| February | 41 | 37 | ▼ 9.8% |
| March | 32 | 32 | 0.0% |
| April | 30 | 30 | 0.0% |
| May | 29 | 30 | ▲ 3.4% |
| June | 13 | 26 | ▲ 100.0% |
| July | 8 | 27 | ▲ 237.5% |
| August | 29 | – | – |
| September | 30 | – | – |
| October | 1 | – | in progress |
| November | 19 | – | – |
| December | 17 | – | – |
| Year to date (Jan–Jul) | 178 | 220 | ▲ 23.6% |
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 | 76.0% | 89.5% | ▲ 17.7% |
| February | 51.2% | 94.6% | ▲ 84.7% |
| March | 93.8% | 100.0% | ▲ 6.7% |
| April | 73.3% | 70.0% | ▼ 4.5% |
| May | 39.3% | 56.7% | ▲ 44.2% |
| June | 84.6% | 92.3% | ▲ 9.1% |
| July | 57.1% | 100.0% | ▲ 75.0% |
| August | 89.7% | – | – |
| September | 83.3% | – | – |
| October | 100.0% | – | in progress |
| November | 79.0% | – | – |
| December | 50.0% | – | – |
| Year-to-date average (Jan–Jul) | 67.9% | 86.1% | ▲ 26.9% |
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 | 0 | 0 | – |
| February | 0 | 0 | – |
| March | 0 | 3 | – |
| April | 0 | 0 | – |
| May | 1 | 0 | ▼ 100.0% |
| June | 0 | 0 | – |
| July | 1 | 0 | ▼ 100.0% |
| August | 0 | – | – |
| September | 0 | – | – |
| October | 0 | – | in progress |
| November | 0 | – | – |
| December | 1 | – | – |
| Year to date (Jan–Jul) | 2 | 3 | ▲ 50.0% |
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 98.6% 584
- Cancelled 1.4% 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
88 of 8
| Routes | Distance (km) | Avg delay | On time | Departures |
|---|---|---|---|---|
| SAN SJC San Diego International Airport – Mineta San Jose International Airport | 671 | 10.0 min | 76.7% | 61 |
| SMF KOA Sacramento International Airport – Ellison Onizuka Kona International Airport at Keāhole | 3,917 | 9.1 min | 86.2% | 58 |
| SMF DEN Sacramento International Airport – Denver International Airport | 1,460 | 18.4 min | 58.9% | 56 |
| ONT OAK Ontario International Airport – Oakland San Francisco Bay Airport | 582 | -1.1 min | 96.0% | 50 |
| DEN SAN Denver International Airport – San Diego International Airport | 1,371 | -3.0 min | 100.0% | 50 |
| BNA DCA Nashville International Airport – Ronald Reagan Washington National Airport | 903 | 21.7 min | 53.1% | 50 |
| SMF SNA Sacramento International Airport – John Wayne Orange County International Airport | 650 | -0.4 min | 87.9% | 33 |
| RSW MDW Southwest Florida International Airport – Chicago Midway International Airport | 1,782 | -1.1 min | 96.7% | 33 |
Monthly figures
| Period | Departures | With departure delay recorded | On time | Cancelled |
|---|---|---|---|---|
| October 2024 | 9 | 9 | 100.0% | 0 |
| November 2024 | 33 | 33 | 84.9% | 0 |
| December 2024 | 56 | 54 | 77.8% | 2 |
| January 2025 | 25 | 25 | 76.0% | 0 |
| February 2025 | 41 | 41 | 51.2% | 0 |
| March 2025 | 32 | 32 | 93.8% | 0 |
| April 2025 | 30 | 30 | 73.3% | 0 |
| May 2025 | 29 | 28 | 39.3% | 1 |
| June 2025 | 13 | 13 | 84.6% | 0 |
| July 2025 | 8 | 7 | 57.1% | 1 |
| August 2025 | 29 | 29 | 89.7% | 0 |
| September 2025 | 30 | 30 | 83.3% | 0 |
| October 2025 | 1 | 1 | 100.0% | 0 |
| November 2025 | 19 | 19 | 79.0% | 0 |
| December 2025 | 17 | 16 | 50.0% | 1 |
| January 2026 | 38 | 38 | 89.5% | 0 |
| February 2026 | 37 | 37 | 94.6% | 0 |
| March 2026 | 32 | 29 | 100.0% | 3 |
| April 2026 | 30 | 30 | 70.0% | 0 |
| May 2026 | 30 | 30 | 56.7% | 0 |
| June 2026 | 26 | 26 | 92.3% | 0 |
| July 2026 | 27 | 27 | 100.0% | 0 |