Flight number record
UA 635
United Airlines · Hartford to Washington
- Route
- BDL → IAD
- Departs
- 06:00
- Flights
- 355
- Period
- September 2025 to August 2026
Historical statistics for September 2025 to August 2026, not live status. For today’s UA 635, check with United Airlines.
UA 635 earns an A. Nearly every flight arrives inside the 15-minute window the DOT uses to define an on-time arrival, which puts it 16 points better than the national rate of 77.3%. When something does go wrong the average delay runs a little over an hour. That rests on 355 flights, with a median arrival 9 minutes early.
Set against the rest of the country, UA 635's record is 16 points better than the US average of 77.3%. That gap is worth roughly 164 fewer late arrivals for every thousand flights.
Key figures
On time
93.7%
Arrivals under 15 minutes late, of 349 completed flights
Avg delay
70 min
Across delayed arrivals only, not all flights
Cancelled
1.69%
National rate is 1.89%
1 hour+ late
1.4%
National rate is 8.3%
These figures cover 355 flights between September 2025 and August 2026. The median arrival is 9 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 635 flies
UA 635 is scheduled to leave Hartford (BDL) at 06:00 local time and reach Washington (IAD) at 07:26. That slot held for 334 of the 355 scheduled departures in the data, so the figures below describe one steady operation rather than a number that moved around the clock.
- Departs 06:00334 flights94.1%
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 06:00 departure sits in the 5am–8am window. Across every US flight scheduled in that window the on-time rate is 89.3%, and UA 635 runs 4 points better at 93.7%. Early departures usually start with an aircraft that has not flown yet that day, which is most of why the window does well.
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Against the route
UA 635 next to BDL to IAD
Every carrier on BDL to IAD combined arrived on time 84.4% of the time across 1,082 flights, so UA 635 is 9 points ahead of it. United flew 941 flights on the same city pair under all its flight numbers, including this one, and those ran 85.3% on time. Across its whole network United Airlines managed 78.8%, which this flight beats by 15 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| UA 635thin sample | 355 | 93.7% | 70 min | 1.69% | A |
| All United Airlines on BDL–IAD | 941 | 85.3% | 82 min | 1.49% | A |
| All carriers on BDL–IAD | 1,082 | 84.4% | 81 min | 1.94% | B |
| United Airlines, whole network | 830,825 | 78.8% | 73 min | 1.02% | B |
Across the year
UA 635 quarter by quarter
Quarter by quarter UA 635 held fairly steady: 93.4% in Oct–Dec 2025, 90.2% in Jan–Mar 2026, 97.8% in Apr–Jun 2026 and 93.3% in Jul–Sep 2026. A spread of 8 points is about what a sample of this size moves on its own, so the annual figure is a fair summary.
- Jul–Sep 202526 flights—
- Oct–Dec 202592 flights93.4%
- Jan–Mar 202686 flights90.2%
- Apr–Jun 202691 flights97.8%
- Jul–Sep 202660 flights93.3%
Scale runs 80% to 100%. Rows with fewer than 30 flights show a dash.
By weekday, UA 635 ranged from 88.0% on Sunday to 98.1% on Thursday. With about 51 flights behind each day, a spread of 10 points is inside normal variation, so the day you fly is not worth changing for this flight.
Arrival by arrival
How late UA 635 runs when it is late
UA 635 often beats the schedule: 114 of 349 completed flights, 33%, arrived 15 minutes or more early. Most of the lateness is short. 14 of the 22 late arrivals were under half an hour behind, and 5 reached an hour or more.
- 15+ min early114 flights32.7%
- Within 15 min213 flights61.0%
- 15–29 min late14 flights4.0%
- 30–59 min late3 flights0.9%
- 1–2 hours late1 flights0.3%
- 2+ hours late4 flights1.1%
Scale runs 0% to 100%.
Share of 349 completed flights by arrival against schedule.
Only 15 of 349 completed flights left 15 minutes late or more, too few to say how often the time is made up.
The worst days
Worst days for UA 635
The latest arrival of the period was on 17 March 2026, 6 hours 12 minutes behind schedule; most of its delay minutes were filed as a late-arriving aircraft. On four of the five worst days the largest share was filed as carrier-caused (crew, maintenance, fuelling, baggage).
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 17 March 2026 | 6 hours 12 minutes | Late-arriving aircraft |
| 28 July 2026 | 3 hours 45 minutes | Carrier |
| 8 September 2025 | 3 hours 42 minutes | Carrier |
| 1 January 2026 | 3 hours 38 minutes | Carrier |
| 10 August 2026 | 1 hour 29 minutes | Carrier |
Delay causes
Why UA 635 runs late
Carrier accounts for 58% of the 1,545 delay minutes carriers reported here, and the remaining four split what is left.
- 58%Carrier
- 23%Late-arriving aircraft
- 18%National Airspace System
The largest share of delay minutes, 58%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. It accounts for 902 of the 1,545 delay minutes reported here. The split is drawn from 1,545 delay minutes reported on UA 635.
Cancellations sit at 1.69% 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 1.4% 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 eight other city pairs in the data, including IAD to SFO (73), IAD to ABQ (24) and IAD to RDU (24), but none flew often enough under UA 635 to report a rate for. Carriers move flight numbers between routes, so the figures on this page apply to BDL to IAD only.
One caution: this is a thin sample. 355 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 635
For a booking, read UA 635 as 93.7% on time with 1.69% cancelled over 355 flights. Those are rates from the past twelve months, not a forecast for any particular day.
Related
Where to go next
- BDL to IAD, every carrier and departure
- IAD to BDL, the return direction
- 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
- 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.