WN4136
WN4136 (Southwest Airlines) is a multi-stop service on 22 routes, busiest Nashville to Baltimore. Of 560 departures recorded from October 2024 to July 2026, 71.0% left on time, according to the US BTS.
- On-time departures71.0%of 560 flights
- Average delay15.7 min
- July 202658▲ 190.0%vs July 2025
- Cancelled0.9%
- Legs flown under this number22
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 | 7 | 4 | ▼ 42.9% |
| February | 22 | 1 | ▼ 95.5% |
| March | 26 | 27 | ▲ 3.8% |
| April | 26 | 14 | ▼ 46.2% |
| May | 27 | 8 | ▼ 70.4% |
| June | 23 | 53 | ▲ 130.4% |
| July | 20 | 58 | ▲ 190.0% |
| August | 42 | – | – |
| September | 43 | – | – |
| October | 32 | – | in progress |
| November | 27 | – | – |
| December | 29 | – | – |
| Year to date (Jan–Jul) | 151 | 165 | ▲ 9.3% |
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 | 60.0% | 100.0% | ▲ 66.7% |
| February | 76.2% | 100.0% | ▲ 31.3% |
| March | 76.0% | 88.9% | ▲ 17.0% |
| April | 88.5% | 71.4% | ▼ 19.3% |
| May | 74.1% | 37.5% | ▼ 49.4% |
| June | 47.8% | 41.5% | ▼ 13.2% |
| July | 25.0% | 62.1% | ▲ 148.3% |
| August | 85.7% | – | – |
| September | 83.7% | – | – |
| October | 56.3% | – | in progress |
| November | 88.5% | – | – |
| December | 93.1% | – | – |
| Year-to-date average (Jan–Jul) | 63.9% | 71.6% | ▲ 12.0% |
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 | 2 | 0 | ▼ 100.0% |
| February | 1 | 0 | ▼ 100.0% |
| March | 1 | 0 | ▼ 100.0% |
| 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) | 4 | 0 | ▼ 100.0% |
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 99.1% 555
- Cancelled 0.9% 5
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 |
|---|---|---|---|---|
| BNA BWI Nashville International Airport – Baltimore/Washington International Thurgood Marshall Airport | 944 | 8.4 min | 85.5% | 64 |
| PHX SMF Phoenix Sky Harbor International Airport – Sacramento International Airport | 1,040 | -1.7 min | 93.1% | 59 |
| PNS STL Pensacola International Airport – St. Louis Lambert International Airport | 965 | 6.2 min | 89.7% | 58 |
| ONT DEN Ontario International Airport – Denver International Airport | 1,316 | 45.8 min | 34.1% | 44 |
| RNO LAS Reno Tahoe International Airport – Harry Reid International Airport | 556 | 27.5 min | 61.9% | 42 |
| MHT BWI Manchester-Boston Regional Airport – Baltimore/Washington International Thurgood Marshall Airport | 606 | 3.7 min | 88.1% | 42 |
| DEN RNO Denver International Airport – Reno Tahoe International Airport | 1,291 | 41.1 min | 44.1% | 34 |
| ONT OAK Ontario International Airport – Oakland San Francisco Bay Airport | 582 | 1.4 min | 90.9% | 33 |
Monthly figures
| Period | Departures | With departure delay recorded | On time | Cancelled |
|---|---|---|---|---|
| October 2024 | 20 | 20 | 65.0% | 0 |
| November 2024 | 28 | 28 | 85.7% | 0 |
| December 2024 | 23 | 23 | 87.0% | 0 |
| January 2025 | 7 | 5 | 60.0% | 2 |
| February 2025 | 22 | 21 | 76.2% | 1 |
| March 2025 | 26 | 25 | 76.0% | 1 |
| April 2025 | 26 | 26 | 88.5% | 0 |
| May 2025 | 27 | 27 | 74.1% | 0 |
| June 2025 | 23 | 23 | 47.8% | 0 |
| July 2025 | 20 | 20 | 25.0% | 0 |
| August 2025 | 42 | 42 | 85.7% | 0 |
| September 2025 | 43 | 43 | 83.7% | 0 |
| October 2025 | 32 | 32 | 56.3% | 0 |
| November 2025 | 27 | 26 | 88.5% | 1 |
| December 2025 | 29 | 29 | 93.1% | 0 |
| January 2026 | 4 | 4 | 100.0% | 0 |
| February 2026 | 1 | 1 | 100.0% | 0 |
| March 2026 | 27 | 27 | 88.9% | 0 |
| April 2026 | 14 | 14 | 71.4% | 0 |
| May 2026 | 8 | 8 | 37.5% | 0 |
| June 2026 | 53 | 53 | 41.5% | 0 |
| July 2026 | 58 | 58 | 62.1% | 0 |