Flight number record
UA 2136
United Airlines · Boston to Washington
- Route
- BOS → IAD
- Departs
- 19:27
- Flights
- 335
- Period
- September 2025 to August 2026
Historical statistics for September 2025 to August 2026, not live status. For today’s UA 2136, check with United Airlines.
UA 2136 sits in the middle of the pack with a C. About seven flights in ten arrive on time by the DOT's definition, 7 points worse than the national rate of 77.3%. The late ones land an hour and a half behind schedule. That rests on 335 flights, with a median arrival 1 minute early.
The national on-time rate over the same period is 77.3%, so UA 2136 runs 7 points behind the country as a whole. Across a thousand flights that is about 73 extra late arrivals.
Key figures
On time
70.0%
Arrivals under 15 minutes late, of 327 completed flights
Avg delay
84 min
Across delayed arrivals only, not all flights
Cancelled
2.39%
National rate is 1.89%
1 hour+ late
15.0%
National rate is 8.3%
These figures cover 335 flights between September 2025 and August 2026. Beyond the headline rate, 15.0% of arrivals land a full hour or more behind schedule, against 8.3% nationally.
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Schedule
When UA 2136 flies
UA 2136 flies BOS to IAD without a single fixed slot. Its most common scheduled departure was 19:27, used on 96 of 335 flights, with 19:07 (45 flights) and 19:38 (36 flights) next.
- Departs 19:2796 flights28.7%
- Departs 19:0745 flights13.4%
- Departs 19:3836 flights10.7%
Scale runs 0% to 100%.
Share of scheduled departures at each local time. Times used on fewer than one flight in ten are not listed.
A 19:27 departure sits in the 5pm–8pm window. Across every US flight scheduled in that window the on-time rate is 68.0%, and UA 2136 runs 2 points better at 70.0%. By that time of day most aircraft have flown several legs already, and whatever went wrong earlier is still in the schedule.
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Against the route
UA 2136 next to BOS to IAD
Every carrier on BOS to IAD combined arrived on time 83.2% of the time across 1,527 flights, so UA 2136 is 13 points behind it. United flew 1,450 flights on the same city pair under all its flight numbers, including this one, and those ran 83.3% on time. Across its whole network United Airlines managed 78.8%, which this flight trails by 9 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| UA 2136thin sample | 335 | 70.0% | 84 min | 2.39% | C |
| All United Airlines on BOS–IAD | 1,450 | 83.3% | 78 min | 2.28% | B |
| All carriers on BOS–IAD | 1,527 | 83.2% | 85 min | 3.01% | B− |
| United Airlines, whole network | 830,825 | 78.8% | 73 min | 1.02% | B |
Across the year
UA 2136 quarter by quarter
UA 2136 did not run the same all year. Its best quarter was Jan–Mar 2026 at 86.5% on time and its weakest Jul–Sep 2025 at 46.7%, a swing of 40 points on roughly 67 flights a quarter. The twelve-month rate averages over that, so if you are flying in a weak quarter the quarter's own figure is the better guide.
- Jul–Sep 202530 flights46.7%
- Oct–Dec 202575 flights67.6%
- Jan–Mar 202679 flights86.5%
- Apr–Jun 202691 flights74.4%
- Jul–Sep 202660 flights57.6%
Scale runs 40% to 90%.
By weekday, UA 2136 did best on Saturday at 91.3% on time and worst on Sunday at 55.3%. Each day rests on about 48 flights, so a gap of 36 points is worth noticing but could still narrow in another year.
Arrival by arrival
How late UA 2136 runs when it is late
The 98 late arrivals split 28 under half an hour, 21 between 30 and 60 minutes, and 49 an hour or more.
- 15+ min early58 flights17.7%
- Within 15 min171 flights52.3%
- 15–29 min late28 flights8.6%
- 30–59 min late21 flights6.4%
- 1–2 hours late25 flights7.6%
- 2+ hours late24 flights7.3%
Scale runs 0% to 100%.
Share of 327 completed flights by arrival against schedule.
14 of 101 late departures made up the time and arrived on time, 14% of them. 11 flights left on time and still arrived late.
The worst days
Worst days for UA 2136
The latest arrival of the period was on 5 July 2026, 6 hours 50 minutes behind schedule; most of its delay minutes were filed as national airspace system delay. On four of the five worst days the largest share was filed as a late-arriving aircraft.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 5 July 2026 | 6 hours 50 minutes | National Airspace System |
| 25 September 2025 | 6 hours 33 minutes | Late-arriving aircraft |
| 13 October 2025 | 4 hours 19 minutes | Late-arriving aircraft |
| 24 September 2025 | 4 hours 9 minutes | Late-arriving aircraft |
| 10 August 2026 | 4 hours 8 minutes | Late-arriving aircraft |
Delay causes
Why UA 2136 runs late
Late-arriving aircraft accounts for 69% of the 8,244 delay minutes carriers reported here, and the remaining four split what is left.
- 69%Late-arriving aircraft
- 20%National Airspace System
- 10%Carrier
- 1%Extreme weather
69% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 8,244 reported delay minutes here, that single category outweighs weather by 67 to one. The split is drawn from 8,244 delay minutes reported on UA 2136.
Cancellations sit at 2.39% against a national 1.89%, which is ordinary. Diversions add another 0.00%.
Connections and routes
What a delay on this flight costs
15.0% of arrivals land a full hour or more behind schedule, against 8.3% nationally. Ninety minutes is the honest minimum for a connection here, and two hours if the onward flight is on a separate ticket.
The same number turns up on three other city pairs in the data, including IAH to BOS (32), SFO to BOS (23) and IAD to IAH (19), but none flew often enough under UA 2136 to report a rate for. Carriers move flight numbers between routes, so the figures on this page apply to BOS to IAD only.
One caution: this is a thin sample. 335 flights over twelve months is enough to clear this site's floor but not enough to pin the rate down tightly, and a single bad week moves it by more than a point. Treat the grade as a rough reading.
What to do with this
Booking UA 2136
For a booking, UA 2136 is a flight to put a long connection behind. 15.0% of its completed flights arrived an hour or more late, which a short layover will not absorb. If the onward flight is on a separate ticket, the risk sits with you.
Related
Where to go next
- BOS to IAD, every carrier and departure
- IAD to BOS, the return direction
- United Airlines 721 on the same route76.6%
- United Airlines 2098 on the same route89.7%
- United Airlines 1734 on the same route96.1%
- Boston Logan International (BOS) delay statistics
- Washington Dulles International (IAD) delay statistics
- United Airlines on-time record
- Every United Airlines flight number with a record
- The most and least reliable flight numbers in the US
- Why the first flight of the morning is statistically safest
A flight number here means United Airlines’s own number as it reports to the DOT. How the figures are computed is on the methodology page.
Source: US DOT Bureau of Transportation Statistics, on-time performance data, September 2025 to August 2026. Last updated ; recomputed monthly. How this data is collected.