WN3997
WN3997 (Southwest Airlines) is a multi-stop service on 22 routes, busiest Houston to Denver. Of 443 departures recorded from October 2024 to July 2026, 80.5% left on time, according to the US BTS.
- On-time departures80.5%of 443 flights
- Average delay10.1 min
- July 202627▼ 12.9%vs July 2025
- Cancelled0.5%
- Legs flown under this number22
Recorded departures by month
All legs under this number combined; see the leg table.
Months without data are left blank.
The most recent periods18 periods
| Period | Departures 2025 | Departures 2026 | Change vs last year |
|---|---|---|---|
| January | 2 | 33 | ▲ 1,550.0% |
| February | – | 43 | – |
| March | 32 | 37 | ▲ 15.6% |
| April | 9 | 15 | ▲ 66.7% |
| May | 1 | 10 | ▲ 900.0% |
| June | 26 | 25 | ▼ 3.8% |
| July | 31 | 27 | ▼ 12.9% |
| August | 31 | – | – |
| September | 30 | – | – |
| October | 5 | – | in progress |
| November | 24 | – | – |
| December | 18 | – | – |
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 periods18 periods
| Period | On time 2025 | On time 2026 | Change vs last year |
|---|---|---|---|
| January | 100.0% | 90.6% | ▼ 9.4% |
| February | – | 95.4% | – |
| March | 62.5% | 38.9% | ▼ 37.8% |
| April | 77.8% | 73.3% | ▼ 5.7% |
| May | 100.0% | 100.0% | 0.0% |
| June | 80.8% | 72.0% | ▼ 10.9% |
| July | 93.6% | 55.6% | ▼ 40.6% |
| August | 100.0% | – | – |
| September | 96.7% | – | – |
| October | 80.0% | – | in progress |
| November | 79.2% | – | – |
| December | 100.0% | – | – |
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 periods18 periods
| Period | Cancelled 2025 | Cancelled 2026 | Change vs last year |
|---|---|---|---|
| January | 0 | 1 | – |
| February | – | 0 | – |
| March | 0 | 1 | – |
| April | 0 | 0 | – |
| May | 0 | 0 | – |
| June | 0 | 0 | – |
| July | 0 | 0 | – |
| August | 0 | – | – |
| September | 0 | – | – |
| October | 0 | – | in progress |
| November | 0 | – | – |
| December | 0 | – | – |
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 99.5% 441
- Cancelled 0.5% 2
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
7| Routes | Distance (km) | Avg delay | On time | Departures |
|---|---|---|---|---|
| HOU DEN William P. Hobby Airport – Denver International Airport | 1,422 | 2.1 min | 88.5% | 61 |
| MHT BWI Manchester-Boston Regional Airport – Baltimore/Washington International Thurgood Marshall Airport | 606 | -2.1 min | 96.6% | 58 |
| TPA ATL Tampa International Airport – Hartsfield Jackson Atlanta International Airport | 655 | 30.0 min | 63.3% | 49 |
| ABQ MDW Albuquerque International Sunport – Chicago Midway International Airport | 1,801 | 6.0 min | 97.8% | 47 |
| ONT SJC Ontario International Airport – Mineta San Jose International Airport | 536 | 4.3 min | 90.5% | 42 |
| SAN MDW San Diego International Airport – Chicago Midway International Airport | 2,776 | 14.1 min | 63.6% | 33 |
| RSW MDW Southwest Florida International Airport – Chicago Midway International Airport | 1,782 | 31.8 min | 34.4% | 33 |
Monthly figures
| Period | Departures | With departure delay recorded | On time | Cancelled |
|---|---|---|---|---|
| October 2024 | 20 | 20 | 75.0% | 0 |
| November 2024 | 10 | 10 | 90.0% | 0 |
| December 2024 | 14 | 14 | 85.7% | 0 |
| January 2025 | 2 | 2 | 100.0% | 0 |
| March 2025 | 32 | 32 | 62.5% | 0 |
| April 2025 | 9 | 9 | 77.8% | 0 |
| May 2025 | 1 | 1 | 100.0% | 0 |
| June 2025 | 26 | 26 | 80.8% | 0 |
| July 2025 | 31 | 31 | 93.6% | 0 |
| August 2025 | 31 | 31 | 100.0% | 0 |
| September 2025 | 30 | 30 | 96.7% | 0 |
| October 2025 | 5 | 5 | 80.0% | 0 |
| November 2025 | 24 | 24 | 79.2% | 0 |
| December 2025 | 18 | 18 | 100.0% | 0 |
| January 2026 | 33 | 32 | 90.6% | 1 |
| February 2026 | 43 | 43 | 95.4% | 0 |
| March 2026 | 37 | 36 | 38.9% | 1 |
| April 2026 | 15 | 15 | 73.3% | 0 |
| May 2026 | 10 | 10 | 100.0% | 0 |
| June 2026 | 25 | 25 | 72.0% | 0 |
| July 2026 | 27 | 27 | 55.6% | 0 |