Flight number record
UA 2451
United Airlines · Houston to Orlando
- Route
- IAH → MCO
- Departs
- 18:30
- Flights
- 336
- Period
- July 2025 to June 2026
Historical statistics for July 2025 to June 2026, not live status. For today’s UA 2451, check with United Airlines.
UA 2451 lands a B+, 2 points better than the national rate of 77.6%. About one flight in five arrives 15 minutes late or worse, and those flights are late by about an hour on average. That is a workable record, not a spotless one. That rests on 336 flights, with a median arrival 7 minutes early.
Key figures
On time
79.9%
Arrivals under 15 minutes late, of 333 completed flights
Avg delay
64 min
Across delayed arrivals only, not all flights
Cancelled
0.60%
National rate is 1.81%
1 hour+ late
7.5%
National rate is 8.1%
These figures cover 336 flights between July 2025 and June 2026. The median arrival is 7 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.
Schedule
When UA 2451 flies
UA 2451 flies IAH to MCO without a single fixed slot. Its most common scheduled departure was 18:30, used on 68 of 336 flights, with 18:33 (58 flights) and 18:35 (58 flights) next. Carriers retime flights through the season, so the rates here blend slightly different positions in the aircraft's day.
- Departs 18:3068 flights20.2%
- Departs 18:3358 flights17.3%
- Departs 18:3558 flights17.3%
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 18:30 departure sits in the 5pm–8pm window. Across every US flight scheduled in that window the on-time rate is 68.2%, and UA 2451 runs 12 points better at 79.9%. 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 2451 next to IAH to MCO
Every carrier on IAH to MCO combined arrived on time 81.6% of the time across 3,669 flights, so UA 2451 is 2 points behind it. United flew 2,471 flights on the same city pair under all its flight numbers, including this one, and those ran 85.1% on time. Across its whole network United Airlines managed 79.0%, close to this flight's figure.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| UA 2451thin sample | 336 | 79.9% | 64 min | 0.60% | B+ |
| All United Airlines on IAH–MCO | 2,471 | 85.1% | 71 min | 0.65% | A+ |
| All carriers on IAH–MCO | 3,669 | 81.6% | 82 min | 1.01% | B |
| United Airlines, whole network | 821,041 | 79.0% | 72 min | 1.01% | B |
Across the year
UA 2451 quarter by quarter
Quarter by quarter UA 2451 held fairly steady: 79.7% in Jul–Sep 2025, 76.1% in Oct–Dec 2025, 83.9% in Jan–Mar 2026 and 80.0% in Apr–Jun 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 202574 flights79.7%
- Oct–Dec 202592 flights76.1%
- Jan–Mar 202690 flights83.9%
- Apr–Jun 202680 flights80.0%
Scale runs 70% to 90%. Rows with fewer than 30 flights show a dash.
By weekday, UA 2451 did best on Wednesday at 86.7% on time and worst on Sunday at 70.8%. Each day rests on about 48 flights, so a gap of 16 points is worth noticing but could still narrow in another year.
Delay causes
Why UA 2451 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 4,268 reported delay minutes.
- 33%Late-arriving aircraft
- 30%National Airspace System
- 22%Carrier
- 14%Extreme weather
Extreme weather accounts for 14% of delay minutes, well above the single-digit share typical across the system. Weather delays are lumpy: they arrive as whole bad days rather than as a steady drag, so the quarterly figures above are the more useful view of the risk. The national share is 6%, so this operation carries roughly 2.2 times the usual weather exposure. The split is drawn from 4,268 delay minutes reported on UA 2451.
Cancellations are rare at 0.60%, below the national 1.81% 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
7.5% of arrivals land an hour or more late, close to the national 8.1%. That is the figure that decides a connection, and it says a 60 to 75 minute layover is reasonable here while anything under 45 minutes is a bet. Most delays on this route last about an hour, which a normal layover absorbs.
The 854 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. It is also long enough that the aircraft usually flies three or four legs a day rather than six, which slows how fast delay compounds.
The same number turns up on seven other city pairs in the data, including LGA to IAH (86), EWR to IAH (37) and SNA to IAH (23), but none flew often enough under UA 2451 to report a rate for. Carriers move flight numbers between routes, so the figures on this page apply to IAH to MCO only.
One caution: this is a thin sample. 336 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 2451
For a booking, read UA 2451 as 79.9% on time with 0.60% cancelled over 336 flights. Those are rates from the past twelve months, not a forecast for any particular day.
Related
Where to go next
- IAH to MCO, every carrier and departure
- MCO to IAH, the return direction
- United Airlines 2662 on the same route86.5%
- United Airlines 496 on the same route79.6%
- United Airlines 2245 on the same route93.9%
- United Airlines 1571 on the same route80.1%
- Frontier Airlines 1418 on the same route79.1%
- George Bush Intercontinental (IAH) delay statistics
- Orlando International (MCO) 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, July 2025 to June 2026. Last updated 15 September 2026; recomputed monthly. How this data is collected.