UA421
UA421 (United Airlines) is a multi-stop service on 11 routes, busiest Denver to Milwaukee. Of 706 departures recorded from October 2024 to July 2026, 79.4% left on time, according to the US BTS.
- On-time departures79.4%of 706 flights
- Average delay14.1 min
- July 202631▲ 0.0%vs July 2025
- Cancelled0.3%
- Legs flown under this number11
Recorded departures by month
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 | 28 | 36 | ▲ 28.6% |
| February | 20 | 28 | ▲ 40.0% |
| March | 29 | 55 | ▲ 89.7% |
| April | 30 | 30 | 0.0% |
| May | 31 | 31 | 0.0% |
| June | 30 | 30 | 0.0% |
| July | 31 | 31 | 0.0% |
| August | 31 | – | – |
| September | 30 | – | – |
| October | 37 | – | in progress |
| November | 59 | – | – |
| December | 46 | – | – |
| Year to date (Jan–Jul) | 199 | 241 | ▲ 21.1% |
according to the US BTS · October 2024 → July 2026
On-time departures by month
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 | 85.7% | 83.3% | ▼ 2.8% |
| February | 90.0% | 81.5% | ▼ 9.5% |
| March | 86.2% | 81.8% | ▼ 5.1% |
| April | 73.3% | 93.3% | ▲ 27.3% |
| May | 61.3% | 96.8% | ▲ 57.9% |
| June | 56.7% | 80.0% | ▲ 41.2% |
| July | 48.4% | 74.2% | ▲ 53.3% |
| August | 51.6% | – | – |
| September | 83.3% | – | – |
| October | 97.3% | – | in progress |
| November | 88.1% | – | – |
| December | 71.7% | – | – |
| Year-to-date average (Jan–Jul) | 71.7% | 84.4% | ▲ 17.8% |
according to the US BTS · October 2024 → July 2026
Average departure delay by month
according to the US BTS · October 2024 → July 2026
Cancelled departures by month
The most recent periods19 periods
| Period | Cancelled 2025 | Cancelled 2026 | Change vs last year |
|---|---|---|---|
| January | 0 | 0 | – |
| February | 0 | 1 | – |
| March | 0 | 0 | – |
| April | 0 | 0 | – |
| May | 0 | 0 | – |
| June | 0 | 0 | – |
| July | 0 | 0 | – |
| August | 0 | – | – |
| September | 0 | – | – |
| October | 0 | – | in progress |
| November | 0 | – | – |
| December | 0 | – | – |
| Year to date (Jan–Jul) | 0 | 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 99.7% 704
- Cancelled 0.3% 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
6| Routes | Distance (km) | Avg delay | On time | Departures |
|---|---|---|---|---|
| DEN MKE Denver International Airport – General Mitchell International Airport | 1,438 | 27.0 min | 70.4% | 240 |
| SNA DEN John Wayne Orange County International Airport – Denver International Airport | 1,360 | 3.6 min | 88.2% | 187 |
| SLC DEN Salt Lake City International Airport – Denver International Airport | 628 | 3.3 min | 82.7% | 75 |
| DEN IAD Denver International Airport – Washington Dulles International Airport | 2,332 | 10.2 min | 80.6% | 72 |
| GJT DEN Grand Junction Regional Airport – Denver International Airport | 341 | 14.5 min | 78.6% | 56 |
| DEN MCO Denver International Airport – Orlando International Airport | 2,486 | -1.7 min | 93.3% | 31 |
Monthly figures
| Period | Departures | With departure delay recorded | On time | Cancelled |
|---|---|---|---|---|
| October 2024 | 16 | 16 | 93.8% | 0 |
| November 2024 | 13 | 13 | 92.3% | 0 |
| December 2024 | 34 | 33 | 84.9% | 1 |
| January 2025 | 28 | 28 | 85.7% | 0 |
| February 2025 | 20 | 20 | 90.0% | 0 |
| March 2025 | 29 | 29 | 86.2% | 0 |
| April 2025 | 30 | 30 | 73.3% | 0 |
| May 2025 | 31 | 31 | 61.3% | 0 |
| June 2025 | 30 | 30 | 56.7% | 0 |
| July 2025 | 31 | 31 | 48.4% | 0 |
| August 2025 | 31 | 31 | 51.6% | 0 |
| September 2025 | 30 | 30 | 83.3% | 0 |
| October 2025 | 37 | 37 | 97.3% | 0 |
| November 2025 | 59 | 59 | 88.1% | 0 |
| December 2025 | 46 | 46 | 71.7% | 0 |
| January 2026 | 36 | 36 | 83.3% | 0 |
| February 2026 | 28 | 27 | 81.5% | 1 |
| March 2026 | 55 | 55 | 81.8% | 0 |
| April 2026 | 30 | 30 | 93.3% | 0 |
| May 2026 | 31 | 31 | 96.8% | 0 |
| June 2026 | 30 | 30 | 80.0% | 0 |
| July 2026 | 31 | 31 | 74.2% | 0 |