Flight number record
UA 2634
United Airlines · Atlanta to Washington
- Route
- ATL → IAD
- Departs
- 19:35
- Flights
- 292
- Period
- September 2025 to August 2026
Historical statistics for September 2025 to August 2026, not live status. For today’s UA 2634, check with United Airlines.
UA 2634 lands a B+, level with the national rate of 77.3%. About one flight in four arrives 15 minutes late or worse, and those flights are late by about an hour on average. That rests on 292 flights, with a median arrival 5 minutes early.
Key figures
On time
76.6%
Arrivals under 15 minutes late, of 291 completed flights
Avg delay
63 min
Across delayed arrivals only, not all flights
Cancelled
0.34%
National rate is 1.89%
1 hour+ late
10.3%
National rate is 8.3%
These figures cover 292 flights between September 2025 and August 2026. Beyond the headline rate, 10.3% of arrivals land a full hour or more behind schedule, against 8.3% nationally.
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Schedule
When UA 2634 flies
UA 2634 flies ATL to IAD without a single fixed slot. Its most common scheduled departure was 19:35, used on 81 of 292 flights, with 19:32 (69 flights) and 19:34 (32 flights) next.
- Departs 19:3581 flights27.7%
- Departs 19:3269 flights23.6%
- Departs 19:3432 flights11.0%
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 19:35 departure sits in the 5pm–8pm window. Across every US flight scheduled in that window the on-time rate is 68.0%, and UA 2634 runs 9 points better at 76.6%. 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 2634 next to ATL to IAD
Every carrier on ATL to IAD combined arrived on time 76.4% of the time across 4,005 flights, so UA 2634 is about level with it. United flew 1,091 flights on the same city pair under all its flight numbers, including this one, and those ran 81.6% on time. Across its whole network United Airlines managed 78.8%, which this flight trails by 2 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| UA 2634thin sample | 292 | 76.6% | 63 min | 0.34% | B+ |
| All United Airlines on ATL–IAD | 1,091 | 81.6% | 78 min | 0.92% | B+ |
| All carriers on ATL–IAD | 4,005 | 76.4% | 79 min | 2.12% | B |
| United Airlines, whole network | 830,825 | 78.8% | 73 min | 1.02% | B |
Across the year
UA 2634 quarter by quarter
UA 2634 did not run the same all year. Its best quarter was Oct–Dec 2025 at 88.2% on time and its weakest Jul–Sep 2026 at 50.0%, a swing of 38 points on roughly 73 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 202529 flights—
- Oct–Dec 202568 flights88.2%
- Jan–Mar 202677 flights81.6%
- Apr–Jun 202684 flights71.4%
- Jul–Sep 202634 flights50.0%
Scale runs 40% to 95%. Rows with fewer than 30 flights show a dash.
By weekday, UA 2634 did best on Monday at 83.0% on time and worst on Sunday at 66.7%. Each day rests on about 42 flights, so a gap of 16 points is worth noticing but could still narrow in another year.
Arrival by arrival
How late UA 2634 runs when it is late
The 68 late arrivals split 15 under half an hour, 23 between 30 and 60 minutes, and 30 an hour or more.
- 15+ min early51 flights17.5%
- Within 15 min172 flights59.1%
- 15–29 min late15 flights5.2%
- 30–59 min late23 flights7.9%
- 1–2 hours late23 flights7.9%
- 2+ hours late7 flights2.4%
Scale runs 0% to 100%.
Share of 291 completed flights by arrival against schedule.
Time lost at the gate mostly stays lost. Of 65 departures that left 15 minutes late or more, only 5 made it up before arrival. 8 flights left on time and still arrived late.
The worst days
Worst days for UA 2634
The latest arrival of the period was on 21 July 2026, 4 hours 34 minutes behind schedule; most of its delay minutes were filed as national airspace system delay. The five worst days are spread across July, May and March, with no single month standing out.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 21 July 2026 | 4 hours 34 minutes | National Airspace System |
| 6 May 2026 | 3 hours 34 minutes | Late-arriving aircraft |
| 20 May 2026 | 3 hours 4 minutes | Carrier |
| 13 March 2026 | 2 hours 28 minutes | National Airspace System |
| 6 July 2026 | 2 hours 10 minutes | Carrier |
Delay causes
Why UA 2634 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 4,296 reported delay minutes.
- 41%Late-arriving aircraft
- 33%National Airspace System
- 25%Carrier
- 1%Extreme weather
41% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 4,296 reported delay minutes here, that single category outweighs weather by 31 to one. The split is drawn from 4,296 delay minutes reported on UA 2634.
Cancellations are rare at 0.34%, below the national 1.89% and low enough to earn the plus on the grade. Roughly one flight in 100 is called off; the risk here is arriving late, not not arriving.
Connections and routes
What a delay on this flight costs
10.3% 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 534 miles between these two airports put this in the middle of the US network, around two and a half to three hours of block time. That is enough cruise to absorb a ten-minute late pushback and not enough to absorb thirty.
The same number turns up on four other city pairs in the data, including SFO to BOS (21), ORD to MCO (19) and IAD to ORD (2), but none flew often enough under UA 2634 to report a rate for. Carriers move flight numbers between routes, so the figures on this page apply to ATL to IAD only.
One caution: this is a thin sample. 292 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 2634
For a booking, read UA 2634 as 76.6% on time with 0.34% cancelled over 292 flights. Those are rates from the past twelve months, not a forecast for any particular day.
Related
Where to go next
- ATL to IAD, every carrier and departure
- IAD to ATL, the return direction
- United Airlines 1831 on the same route76.2%
- Delta Air Lines 1695 on the same route75.6%
- Delta Air Lines 2549 on the same route72.8%
- United Airlines 632 on the same route87.0%
- Delta Air Lines 1309 on the same route72.6%
- Delta Air Lines 1444 on the same route87.6%
- Hartsfield-Jackson Atlanta International (ATL) 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.