Flight number record
UA 755
United Airlines · Washington to Boston
- Route
- IAD → BOS
- Departs
- 22:10
- Flights
- 323
- Period
- September 2025 to August 2026
Historical statistics for September 2025 to August 2026, not live status. For today’s UA 755, check with United Airlines.
UA 755 lands a B, 2 points better than the national rate of 77.3%. About one flight in five arrives 15 minutes late or worse, and those flights are late by about an hour on average. That rests on 323 flights, with a median arrival 4 minutes early.
Key figures
On time
79.1%
Arrivals under 15 minutes late, of 316 completed flights
Avg delay
60 min
Across delayed arrivals only, not all flights
Cancelled
2.17%
National rate is 1.89%
1 hour+ late
4.4%
National rate is 8.3%
These figures cover 323 flights between September 2025 and August 2026. The median arrival is 4 minutes early, which is the part an average hides: most flights here are fine, and the on-time rate is decided by a tail of badly late ones. On-time means under 15 minutes late, the DOT's own threshold.
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Schedule
When UA 755 flies
UA 755 flies IAD to BOS without a single fixed slot. Its most common scheduled departure was 22:10, used on 80 of 323 flights, with 22:15 (74 flights) and 22:20 (42 flights) next.
- Departs 22:1080 flights24.8%
- Departs 22:1574 flights22.9%
- Departs 22:2042 flights13.0%
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 22:10 departure sits in the 8pm–5am window. Across every US flight scheduled in that window the on-time rate is 70.1%, and UA 755 runs 9 points better at 79.1%. 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 755 next to IAD to BOS
Every carrier on IAD to BOS combined arrived on time 76.9% of the time across 1,524 flights, so UA 755 is 2 points ahead of it. United flew 1,447 flights on the same city pair under all its flight numbers, including this one, and those ran 77.1% on time. Across its whole network United Airlines managed 78.8%, close to this flight's figure.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| UA 755thin sample | 323 | 79.1% | 60 min | 2.17% | B |
| All United Airlines on IAD–BOS | 1,447 | 77.1% | 70 min | 2.07% | B |
| All carriers on IAD–BOS | 1,524 | 76.9% | 70 min | 2.76% | B |
| United Airlines, whole network | 830,825 | 78.8% | 73 min | 1.02% | B |
Across the year
UA 755 quarter by quarter
UA 755 did not run the same all year. Its best quarter was Apr–Jun 2026 at 88.8% on time and its weakest Jul–Sep 2026 at 66.1%, a swing of 23 points on roughly 81 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 202524 flights—
- Oct–Dec 202564 flights74.6%
- Jan–Mar 202684 flights80.2%
- Apr–Jun 202691 flights88.8%
- Jul–Sep 202660 flights66.1%
Scale runs 60% to 95%. Rows with fewer than 30 flights show a dash.
By weekday, UA 755 did best on Tuesday at 84.1% on time and worst on Thursday at 71.1%. Each day rests on about 46 flights, so a gap of 13 points is worth noticing but could still narrow in another year.
Arrival by arrival
How late UA 755 runs when it is late
UA 755 often beats the schedule: 81 of 316 completed flights, 26%, arrived 15 minutes or more early. The 66 late arrivals split 29 under half an hour, 23 between 30 and 60 minutes, and 14 an hour or more.
- 15+ min early81 flights25.6%
- Within 15 min169 flights53.5%
- 15–29 min late29 flights9.2%
- 30–59 min late23 flights7.3%
- 1–2 hours late7 flights2.2%
- 2+ hours late7 flights2.2%
Scale runs 0% to 100%.
Share of 316 completed flights by arrival against schedule.
17 of 68 late departures made up the time and arrived on time, 25% of them. 15 flights left on time and still arrived late.
The worst days
Worst days for UA 755
The latest arrival of the period was on 3 January 2026, 11 hours 1 minute behind schedule; most of its delay minutes were filed as carrier-caused (crew, maintenance, fuelling, baggage). Three of the five worst days fell in July 2026.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 3 January 2026 | 11 hours 1 minute | Carrier |
| 21 July 2026 | 4 hours 53 minutes | Late-arriving aircraft |
| 18 July 2026 | 3 hours 36 minutes | Late-arriving aircraft |
| 26 January 2026 | 3 hours 3 minutes | National Airspace System |
| 6 July 2026 | 2 hours 38 minutes | Late-arriving aircraft |
Delay causes
Why UA 755 runs late
Carriers report a reason for every delay minute they cause, in five DOT categories. The split below is by minutes, not by number of flights, so a handful of very long weather delays weighs as much as many short ones. It covers 3,958 reported delay minutes.
- 38%Carrier
- 32%National Airspace System
- 25%Late-arriving aircraft
- 4%Extreme weather
The largest share of delay minutes, 38%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. It accounts for 1,515 of the 3,958 delay minutes reported here. The split is drawn from 3,958 delay minutes reported on UA 755.
Cancellations sit at 2.17% against a national 1.89%, which is ordinary. Diversions add another 0.00%.
Connections and routes
What a delay on this flight costs
Badly late arrivals are rare here: only 4.4% land an hour or more behind schedule, against 8.3% nationally. Connections built on this flight are about as safe as US domestic connections get, though a cancelled flight still ignores every layover you give it.
The same number turns up on five other city pairs in the data, including SAN to IAD (106), SFO to IAD (98) and RNO to SFO (53), but none flew often enough under UA 755 to report a rate for. Carriers move flight numbers between routes, so the figures on this page apply to IAD to BOS only.
One caution: this is a thin sample. 323 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 755
For a booking, read UA 755 as 79.1% on time with 2.17% cancelled over 323 flights. Those are rates from the past twelve months, not a forecast for any particular day.
Related
Where to go next
- IAD to BOS, every carrier and departure
- BOS to IAD, the return direction
- United Airlines 688 on the same route61.4%
- United Airlines 641 on the same route92.3%
- Washington Dulles International (IAD) delay statistics
- Boston Logan International (BOS) 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
- Worst months to fly in the US, ranked by the data
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.