WN4852
WN4852 (Southwest Airlines) is a multi-stop service on 16 routes, busiest San Jose to Ontario. Of 273 departures recorded from October 2024 to July 2026, 73.5% left on time, according to the US BTS.
- On-time departures73.5%of 273 flights
- Average delay15.3 min
- July 202614▼ 54.8%vs July 2025
- Cancelled1.8%
- Legs flown under this number16
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 | 28 | 6 | ▼ 78.6% |
| February | 20 | 21 | ▲ 5.0% |
| March | 4 | 2 | ▼ 50.0% |
| April | – | – | – |
| May | – | – | – |
| June | 26 | 12 | ▼ 53.8% |
| July | 31 | 14 | ▼ 54.8% |
| August | 4 | – | – |
| September | – | – | – |
| October | 15 | – | in progress |
| November | 9 | – | – |
| December | 22 | – | – |
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 | 96.3% | 50.0% | ▼ 48.1% |
| February | 100.0% | 40.0% | ▼ 60.0% |
| March | 100.0% | 50.0% | ▼ 50.0% |
| April | – | – | – |
| May | – | – | – |
| June | 96.2% | 8.3% | ▼ 91.3% |
| July | 87.1% | 28.6% | ▼ 67.2% |
| August | 100.0% | – | – |
| September | – | – | – |
| October | 64.3% | – | in progress |
| November | 55.6% | – | – |
| December | 33.3% | – | – |
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 | 1 | 0 | ▼ 100.0% |
| February | 0 | 1 | – |
| March | 0 | 0 | – |
| April | – | – | – |
| May | – | – | – |
| June | 0 | 0 | – |
| July | 0 | 0 | – |
| August | 1 | – | – |
| September | – | – | – |
| October | 1 | – | in progress |
| November | 0 | – | – |
| December | 1 | – | – |
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 98.2% 268
- Cancelled 1.8% 5
Share of all recorded flights in the period, all legs. · Oct 14, 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 |
|---|---|---|---|---|
| SJC ONT Mineta San Jose International Airport – Ontario International Airport | 536 | -3.0 min | 98.5% | 69 |
| MCO ORD Orlando International Airport – Chicago O'Hare International Airport | 1,620 | 4.7 min | 91.7% | 61 |
| ONT LAS Ontario International Airport – Harry Reid International Airport | 317 | 2.0 min | 96.8% | 31 |
Monthly figures
| Period | Departures | With departure delay recorded | On time | Cancelled |
|---|---|---|---|---|
| October 2024 | 9 | 9 | 55.6% | 0 |
| November 2024 | 27 | 27 | 100.0% | 0 |
| December 2024 | 23 | 23 | 95.7% | 0 |
| January 2025 | 28 | 27 | 96.3% | 1 |
| February 2025 | 20 | 20 | 100.0% | 0 |
| March 2025 | 4 | 4 | 100.0% | 0 |
| June 2025 | 26 | 26 | 96.2% | 0 |
| July 2025 | 31 | 31 | 87.1% | 0 |
| August 2025 | 4 | 3 | 100.0% | 1 |
| October 2025 | 15 | 14 | 64.3% | 1 |
| November 2025 | 9 | 9 | 55.6% | 0 |
| December 2025 | 22 | 21 | 33.3% | 1 |
| January 2026 | 6 | 6 | 50.0% | 0 |
| February 2026 | 21 | 20 | 40.0% | 1 |
| March 2026 | 2 | 2 | 50.0% | 0 |
| June 2026 | 12 | 12 | 8.3% | 0 |
| July 2026 | 14 | 14 | 28.6% | 0 |