Flight number record
UA 2456
United Airlines · Houston to Seattle
- Route
- IAH → SEA
- Departs
- 19:50
- Flights
- 312
- Period
- July 2025 to June 2026
Historical statistics for July 2025 to June 2026, not live status. For today’s UA 2456, check with United Airlines.
UA 2456 sits in the middle of the pack with a C. About seven flights in ten arrive on time by the DOT's definition, 9 points worse than the national rate of 77.6%. The late ones land roughly 50 minutes behind schedule. That rests on 312 flights, with a median arrival 2 minutes late.
The national on-time rate over the same period is 77.6%, so UA 2456 runs 9 points behind the country as a whole. Across a thousand flights that is about 89 extra late arrivals.
Key figures
On time
68.7%
Arrivals under 15 minutes late, of 307 completed flights
Avg delay
48 min
Across delayed arrivals only, not all flights
Cancelled
1.28%
National rate is 1.81%
1 hour+ late
9.1%
National rate is 8.1%
These figures cover 312 flights between July 2025 and June 2026. Beyond the headline rate, 9.1% of arrivals land a full hour or more behind schedule. That is the number that wrecks a connection, and it is not visible in an on-time percentage alone.
Schedule
When UA 2456 flies
UA 2456 flies IAH to SEA without a single fixed slot. Its most common scheduled departure was 19:50, used on 119 of 312 flights, with 19:57 (76 flights) and 20:05 (42 flights) next. Carriers retime flights through the season, so the rates here blend slightly different positions in the aircraft's day.
- Departs 19:50119 flights38.1%
- Departs 19:5776 flights24.4%
- Departs 20:0542 flights13.5%
Scale runs 0% to 100%. Rows with fewer than 30 flights show a dash.
Share of scheduled departures at each local time. Times used on fewer than one flight in ten are not listed.
A 19:50 departure sits in the 5pm–8pm window. Across every US flight scheduled in that window the on-time rate is 68.2%, and UA 2456 runs level with that at 68.7%. By that time of day most aircraft have flown several legs already, and whatever went wrong earlier is still in the schedule.
Against the route
UA 2456 next to IAH to SEA
Every carrier on IAH to SEA combined arrived on time 77.5% of the time across 2,095 flights, so UA 2456 is 9 points behind it. United flew 1,243 flights on the same city pair under all its flight numbers, including this one, and those ran 76.8% on time. Across its whole network United Airlines managed 79.0%, which this flight trails by 10 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| UA 2456thin sample | 312 | 68.7% | 48 min | 1.28% | C |
| All United Airlines on IAH–SEA | 1,243 | 76.8% | 56 min | 0.40% | B+ |
| All carriers on IAH–SEA | 2,095 | 77.5% | 54 min | 0.53% | B+ |
| United Airlines, whole network | 821,041 | 79.0% | 72 min | 1.01% | B |
Across the year
UA 2456 quarter by quarter
UA 2456 did not run the same all year. Its best quarter was Apr–Jun 2026 at 80.5% on time and its weakest Jul–Sep 2025 at 52.3%, a swing of 28 points on roughly 78 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 202591 flights52.3%
- Oct–Dec 202590 flights74.2%
- Jan–Mar 202690 flights74.2%
- Apr–Jun 202641 flights80.5%
Scale runs 45% to 85%. Rows with fewer than 30 flights show a dash.
By weekday, UA 2456 did best on Tuesday at 86.0% on time and worst on Saturday at 59.5%. Each day rests on about 45 flights, so a gap of 27 points is worth noticing but could still narrow in another year.
Delay causes
Why UA 2456 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 4,646 reported delay minutes.
- 35%Carrier
- 31%National Airspace System
- 30%Late-arriving aircraft
- 4%Extreme weather
The largest share of delay minutes, 35%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. Unlike weather, that is a management outcome, and it is the category where the gap between two carriers on the same schedule is genuinely earned. It accounts for 1,619 of the 4,646 delay minutes reported here. The split is drawn from 4,646 delay minutes reported on UA 2456.
Cancellations sit at 1.28% against a national 1.81%, which is ordinary. Diversions add another 0.32%.
Connections and routes
What a delay on this flight costs
For anyone connecting, the number to weigh is not the on-time rate but the tail behind it. 9.1% of arrivals land a full hour or more behind schedule, against 8.1% nationally. A 45-minute layover does not survive that, and no amount of walking quickly changes it. Ninety minutes is the honest minimum here, and two hours if the onward flight is on a separate ticket.
At 1,874 miles this is transcontinental flying, and long routes get a quiet structural advantage. Scheduled block time on a flight this length carries more padding in absolute minutes, so a twenty-minute late departure often still becomes an on-time arrival. Read the on-time rate here as slightly flattering next to a short-haul route with the same operational quality.
The same number turns up on six other city pairs in the data, including MCO to IAH (175), DCA to IAH (34) and IND to IAH (30), but none flew often enough under UA 2456 to report a rate for. Carriers move flight numbers between routes, so the figures on this page apply to IAH to SEA only.
One caution: this is a thin sample. 312 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 2456
For a booking, UA 2456 is one of the weaker ways to fly IAH to SEA: 9 points below the route as a whole. If the schedule allows, compare it with the other departures listed on the route page before settling on this one.
Related
Where to go next
- IAH to SEA, every carrier and departure
- SEA to IAH, the return direction
- Alaska Airlines 439 on the same route67.4%
- Alaska Airlines 453 on the same route87.1%
- George Bush Intercontinental (IAH) delay statistics
- Seattle-Tacoma International (SEA) 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
- How often a connection fails at the major US hubs
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, July 2025 to June 2026. Last updated 15 September 2026; recomputed monthly. How this data is collected.