Flight profile · United Airlines
UA1831
Atlanta (ATL) to Washington (IAD) · scheduled 2:38 PM – 4:30 PM
How UA1831 performs
475 operations, 2025-03-06 to 2026-06-30.
UA1831 arrived on time 76.6% of the time, against 79.2% for all ATL → IAD flights — this specific departure is 2.6 percentage points worse than the route as a whole. Against United Airlines’s own flights on this route it is 5.8 points worse.
Source: US DOT Bureau of Transportation Statistics · 475 operations between 2025-03-06 to 2026-06-30
Against the rest of the route
| On time | Cancelled | Median delay | Severe | Flights | |
|---|---|---|---|---|---|
| UA1831 | 76.6% | 0.42% | -3 min | 11.3% | 475 |
| United Airlines on ATL → IAD | 82.5% | 0.86% | -6 min | 7.2% | 3,360 |
| All ATL → IAD flights | 79.2% | 1.37% | -4 min | 8.2% | 10,941 |
Source: FlyerIntel analysis of US DOT BTS data · 2025-03-06 to 2026-06-30
Other routes UA1831 has flown
A flight number is a slot in a schedule, and carriers reassign it. These are the other city pairs this number served in the analysis period.
| Route | Operated | Flights | On time |
|---|---|---|---|
| IAD→EWR Washington to Newark | 2025-12-18 – 2026-06-30 | 151 | 62.8% |
| ORD→ATL Chicago to Atlanta | 2026-02-12 – 2026-03-04 | 21 | — |
| PBI→EWR West Palm Beach to Newark | 2025-12-20 – 2026-01-03 | 3 | — |
| IAD→SAN Washington to San Diego | 2024-08-19 – 2025-03-29 | 223 | 70.8% |
| EWR→SFO Newark to San Francisco | 2024-05-23 – 2024-08-18 | 88 | — |
| SFO→LAS San Francisco to Las Vegas | 2024-08-01 – 2024-08-18 | 18 | — |
| LAX→LAS Los Angeles to Las Vegas | 2024-03-31 – 2024-05-22 | 53 | — |
| EWR→IAH Newark to Houston | 2024-02-15 – 2024-03-30 | 45 | — |
| EWR→JAX Newark to Jacksonville | 2024-01-09 – 2024-02-14 | 37 | — |
| IAH→AUS Houston to Austin | 2023-12-21 – 2024-01-08 | 17 | — |
| MFE→IAH McAllen to Houston | 2023-11-28 – 2023-12-20 | 23 | — |
| SFO→EWR San Francisco to Newark | 2023-07-01 – 2023-11-27 | 149 | 70.6% |
Because the same number has served different journeys, the statistics above describe only the route UA1831 currently operates. Blending them would produce an average of two different flights.
Why UA1831 runs late
Where US DOT attributed the delay minutes on this flight.
the inbound aircraft was late, so this flight started late
airspace and airport capacity, including weather-driven flow control
crew, maintenance, boarding, fuelling — within the carrier’s control
weather severe enough to stop this flight specifically
Share of the delay minutes US DOT attributed to each cause for UA1831 on ATL → IAD. A single late flight can carry more than one cause, and only delays of fifteen minutes or more are attributed at all.
Other departures on ATL → IAD
Same airports, same journey — and not the same odds of arriving on time.
| Flight | Airline | On time | Median arrival | Operations |
|---|---|---|---|---|
| UA632 | United Airlines | 88.1% | 8 min early | 802 |
| DL2902 | Delta Air Lines | 77.4% | 2 min early | 733 |
| UA2634 | United Airlines | 77.4% | 4 min early | 967 |
| DL2549 | Delta Air Lines | 75.6% | 3 min early | 1,000 |
| DL1695 | Delta Air Lines | 74.9% | 2 min early | 1,024 |
Every departure listed carries at least 600 operations, so the comparison is between figures that mean something. Schedules change; confirm the departure still operates before booking around this.
Data and methodology
Calculated by FlyerIntel from 475 records of UA1831 operating ATL → IAD, published by the US DOT Bureau of Transportation Statistics. A flight counts as delayed when it arrives 15 or more minutes after schedule. Cancelled and diverted flights are excluded from the on-time rate and reported separately. Flight numbers are resolved as carrier plus number plus route, because the same number serves different routes over time.
Full methodology · Report a problem
Analysis last recomputed