Flight profile · United Airlines
UA2136
Boston (BOS) to Washington (IAD) · scheduled 7:20 PM – 9:25 PM
How UA2136 performs
1,059 operations, 2023-07-01 to 2026-06-30.
UA2136 arrived on time 71.9% of the time, against 83.6% for all BOS → IAD flights — this specific departure is 11.7 percentage points worse than the route as a whole. Against United Airlines’s own flights on this route it is 11.7 points worse.
Source: US DOT Bureau of Transportation Statistics · 1,059 operations between 2023-07-01 to 2026-06-30
Against the rest of the route
| On time | Cancelled | Median delay | Severe | Flights | |
|---|---|---|---|---|---|
| UA2136 | 71.9% | 1.70% | -4 min | 13.3% | 1,059 |
| United Airlines on BOS → IAD | 83.6% | 1.28% | -9 min | 6.1% | 4,464 |
| All BOS → IAD flights | 83.6% | 1.27% | -9 min | 6.1% | 4,476 |
Source: FlyerIntel analysis of US DOT BTS data · 2023-07-01 to 2026-06-30
By day of week
Does UA2136 run worse on particular days?
Saturday is historically the most reliable day and Sunday the least, a gap of 16.8 percentage points.
Source: FlyerIntel analysis of US DOT BTS data · 2023-07-01 to 2026-06-30 · Days with fewer than 120 operations are not scored.
Other routes UA2136 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 |
|---|---|---|---|
| IAH→BOS Houston to Boston | 2026-03-29 – 2026-04-29 | 32 | — |
| IAD→IAH Washington to Houston | 2025-12-18 – 2026-01-05 | 19 | — |
| SFO→BOS San Francisco to Boston | 2025-03-30 – 2025-09-24 | 55 | — |
| IAD→LAS Washington to Las Vegas | 2025-06-26 – 2025-07-31 | 35 | — |
| IAD→SEA Washington to Seattle | 2025-05-22 – 2025-05-31 | 9 | — |
| IAD→ATL Washington to Atlanta | 2025-05-01 – 2025-05-21 | 13 | — |
| EWR→BOS Newark to Boston | 2025-02-13 – 2025-03-05 | 15 | — |
| IAD→SFO Washington to San Francisco | 2024-10-28 – 2024-12-02 | 30 | — |
| SFO→DEN San Francisco to Denver | 2023-09-28 – 2023-09-28 | 1 | — |
| IAD→RDU Washington to Raleigh–Durham | 2023-09-05 – 2023-09-27 | 23 | — |
Because the same number has served different journeys, the statistics above describe only the route UA2136 currently operates. Blending them would produce an average of two different flights.
Why UA2136 runs late
Where US DOT attributed the delay minutes on this flight.
the inbound aircraft was late, so this flight started late
crew, maintenance, boarding, fuelling — within the carrier’s control
airspace and airport capacity, including weather-driven flow control
weather severe enough to stop this flight specifically
Share of the delay minutes US DOT attributed to each cause for UA2136 on BOS → 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 BOS → IAD
Same airports, same journey — and not the same odds of arriving on time.
| Flight | Airline | On time | Median arrival | Operations |
|---|---|---|---|---|
| UA2098 | United Airlines | 90.1% | 10 min early | 695 |
| UA721 | United Airlines | 74.1% | 0 min early | 641 |
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 1,059 records of UA2136 operating BOS → 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.
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