UA599
UA599 (United Airlines) is a multi-stop service on 12 routes, busiest Dulles to Denver. Of 664 departures recorded from October 2024 to July 2026, 78.6% left on time, according to the US BTS.
- On-time departures78.6%of 664 flights
- Average delay13.7 min
- July 202631▲ 0.0%vs July 2025
- Cancelled0.6%
- Legs flown under this number12
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 | 26 | 31 | ▲ 19.2% |
| February | 21 | 28 | ▲ 33.3% |
| March | 26 | 31 | ▲ 19.2% |
| 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 | 31 | – | in progress |
| November | 30 | – | – |
| December | 31 | – | – |
| Year to date (Jan–Jul) | 195 | 212 | ▲ 8.7% |
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 | 80.8% | 73.3% | ▼ 9.2% |
| February | 90.5% | 96.4% | ▲ 6.6% |
| March | 92.3% | 67.7% | ▼ 26.6% |
| April | 90.0% | 86.7% | ▼ 3.7% |
| May | 83.9% | 80.7% | ▼ 3.8% |
| June | 76.7% | 76.7% | 0.0% |
| July | 93.6% | 58.6% | ▼ 37.3% |
| August | 90.3% | – | – |
| September | 93.3% | – | – |
| October | 93.6% | – | in progress |
| November | 80.0% | – | – |
| December | 64.5% | – | – |
| Year-to-date average (Jan–Jul) | 86.8% | 77.2% | ▼ 11.1% |
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 | 1 | – |
| February | 0 | 0 | – |
| March | 0 | 0 | – |
| April | 0 | 0 | – |
| May | 0 | 0 | – |
| June | 0 | 0 | – |
| July | 0 | 2 | – |
| August | 0 | – | – |
| September | 0 | – | – |
| October | 0 | – | in progress |
| November | 0 | – | – |
| December | 0 | – | – |
| Year to date (Jan–Jul) | 0 | 3 |
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 99.4% 660
- Cancelled 0.6% 4
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 |
|---|---|---|---|---|
| IAD DEN Washington Dulles International Airport – Denver International Airport | 2,332 | 20.6 min | 74.5% | 258 |
| BNA IAH Nashville International Airport – George Bush Intercontinental Airport | 1,057 | 6.1 min | 89.0% | 172 |
| FLL CLE Fort Lauderdale Hollywood International Airport – Cleveland Hopkins International Airport | 1,713 | 5.2 min | 88.9% | 63 |
| CMH SFO John Glenn Columbus International Airport – San Francisco International Airport | 3,403 | 32.4 min | 42.3% | 52 |
| SFO PIT San Francisco International Airport – Pittsburgh International Airport | 3,618 | 12.4 min | 67.5% | 41 |
| DEN FLL Denver International Airport – Fort Lauderdale Hollywood International Airport | 2,739 | 3.4 min | 89.2% | 37 |
Monthly figures
| Period | Departures | With departure delay recorded | On time | Cancelled |
|---|---|---|---|---|
| October 2024 | 23 | 23 | 47.8% | 0 |
| November 2024 | 48 | 48 | 52.1% | 0 |
| December 2024 | 33 | 32 | 75.0% | 1 |
| January 2025 | 26 | 26 | 80.8% | 0 |
| February 2025 | 21 | 21 | 90.5% | 0 |
| March 2025 | 26 | 26 | 92.3% | 0 |
| April 2025 | 30 | 30 | 90.0% | 0 |
| May 2025 | 31 | 31 | 83.9% | 0 |
| June 2025 | 30 | 30 | 76.7% | 0 |
| July 2025 | 31 | 31 | 93.6% | 0 |
| August 2025 | 31 | 31 | 90.3% | 0 |
| September 2025 | 30 | 30 | 93.3% | 0 |
| October 2025 | 31 | 31 | 93.6% | 0 |
| November 2025 | 30 | 30 | 80.0% | 0 |
| December 2025 | 31 | 31 | 64.5% | 0 |
| January 2026 | 31 | 30 | 73.3% | 1 |
| February 2026 | 28 | 28 | 96.4% | 0 |
| March 2026 | 31 | 31 | 67.7% | 0 |
| April 2026 | 30 | 30 | 86.7% | 0 |
| May 2026 | 31 | 31 | 80.7% | 0 |
| June 2026 | 30 | 30 | 76.7% | 0 |
| July 2026 | 31 | 29 | 58.6% | 2 |