WN3787
WN3787 (Southwest Airlines) is a multi-stop service on 25 routes, busiest Chicago to Boston. Of 395 departures recorded from October 2024 to May 2026, 84.7% left on time, according to the US BTS.
- On-time departures84.7%of 395 flights
- Average delay9.8 min
- May 202623▼ 11.5%vs May 2025
- Cancelled0.8%
- Legs flown under this number25
Recorded departures by month
All legs under this number combined; see the leg table.
Months without data are left blank.
The most recent periods15 periods
| Period | Departures 2025 | Departures 2026 | Change vs last year |
|---|---|---|---|
| January | 22 | – | – |
| February | 24 | 11 | ▼ 54.2% |
| March | 30 | 28 | ▼ 6.7% |
| April | 27 | 18 | ▼ 33.3% |
| May | 26 | 23 | ▼ 11.5% |
| June | 34 | – | – |
| July | 35 | – | – |
| August | 39 | – | – |
| September | 39 | – | – |
| October | 17 | – | in progress |
| November | 1 | – | – |
| December | – | – | – |
according to the US BTS · October 2024 → May 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 periods15 periods
| Period | On time 2025 | On time 2026 | Change vs last year |
|---|---|---|---|
| January | 95.5% | – | – |
| February | 91.3% | 100.0% | ▲ 9.5% |
| March | 86.2% | 85.7% | ▼ 0.6% |
| April | 85.2% | 100.0% | ▲ 17.4% |
| May | 69.2% | 91.3% | ▲ 31.9% |
| June | 64.7% | – | – |
| July | 64.7% | – | – |
| August | 87.2% | – | – |
| September | 87.2% | – | – |
| October | 94.1% | – | in progress |
| November | 100.0% | – | – |
| December | – | – | – |
according to the US BTS · October 2024 → May 2026
Average departure delay by month
Months without data are left blank.
according to the US BTS · October 2024 → May 2026
Cancelled departures by month
Months without data are left blank.
The most recent periods15 periods
| Period | Cancelled 2025 | Cancelled 2026 | Change vs last year |
|---|---|---|---|
| January | 0 | – | – |
| February | 1 | 0 | ▼ 100.0% |
| March | 1 | 0 | ▼ 100.0% |
| April | 0 | 0 | – |
| May | 0 | 0 | – |
| June | 0 | – | – |
| July | 1 | – | – |
| August | 0 | – | – |
| September | 0 | – | – |
| October | 0 | – | in progress |
| November | 0 | – | – |
| December | – | – | – |
according to the US BTS · October 2024 → May 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 99.2% 392
- Cancelled 0.8% 3
Share of all recorded flights in the period, all legs. · Oct 12, 2024 → May 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 |
|---|---|---|---|---|
| MDW BOS Chicago Midway International Airport – Boston Logan International Airport | 1,381 | 29.8 min | 65.0% | 61 |
| PHX ONT Phoenix Sky Harbor International Airport – Ontario International Airport | 522 | 17.9 min | 74.0% | 50 |
| MEM MDW Frederick W. Smith International Airport – Chicago Midway International Airport | 774 | 5.4 min | 88.0% | 50 |
| DEN ONT Denver International Airport – Ontario International Airport | 1,316 | 5.2 min | 87.9% | 33 |
Monthly figures
| Period | Departures | With departure delay recorded | On time | Cancelled |
|---|---|---|---|---|
| October 2024 | 19 | 19 | 100.0% | 0 |
| November 2024 | 2 | 2 | 100.0% | 0 |
| January 2025 | 22 | 22 | 95.5% | 0 |
| February 2025 | 24 | 23 | 91.3% | 1 |
| March 2025 | 30 | 29 | 86.2% | 1 |
| April 2025 | 27 | 27 | 85.2% | 0 |
| May 2025 | 26 | 26 | 69.2% | 0 |
| June 2025 | 34 | 34 | 64.7% | 0 |
| July 2025 | 35 | 34 | 64.7% | 1 |
| August 2025 | 39 | 39 | 87.2% | 0 |
| September 2025 | 39 | 39 | 87.2% | 0 |
| October 2025 | 17 | 17 | 94.1% | 0 |
| November 2025 | 1 | 1 | 100.0% | 0 |
| February 2026 | 11 | 11 | 100.0% | 0 |
| March 2026 | 28 | 28 | 85.7% | 0 |
| April 2026 | 18 | 18 | 100.0% | 0 |
| May 2026 | 23 | 23 | 91.3% | 0 |