Flight number record
UA 2451
United Airlines · Houston to Orlando
- Route
- IAH → MCO
- Departs
- 18:26
- Flights
- 339
- Period
- September 2025 to August 2026
Historical statistics for September 2025 to August 2026, not live status. For today’s UA 2451, check with United Airlines.
UA 2451 lands a B+, 3 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 339 flights, with a median arrival 8 minutes early.
Key figures
On time
79.8%
Arrivals under 15 minutes late, of 336 completed flights
Avg delay
65 min
Across delayed arrivals only, not all flights
Cancelled
0.59%
National rate is 1.89%
1 hour+ late
7.4%
National rate is 8.3%
These figures cover 339 flights between September 2025 and August 2026. The median arrival is 8 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 2451 flies
UA 2451 flies IAH to MCO without a single fixed slot. Its most common scheduled departure was 18:26, used on 59 of 339 flights, with 18:35 (58 flights) and 18:33 (58 flights) next.
- Departs 18:2659 flights17.4%
- Departs 18:3558 flights17.1%
- Departs 18:3358 flights17.1%
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 18:26 departure sits in the 5pm–8pm window. Across every US flight scheduled in that window the on-time rate is 68.0%, and UA 2451 runs 12 points better at 79.8%. 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 2451 next to IAH to MCO
Every carrier on IAH to MCO combined arrived on time 83.2% of the time across 3,569 flights, so UA 2451 is 3 points behind it. United flew 2,443 flights on the same city pair under all its flight numbers, including this one, and those ran 86.5% 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 2451thin sample | 339 | 79.8% | 65 min | 0.59% | B+ |
| All United Airlines on IAH–MCO | 2,443 | 86.5% | 71 min | 0.53% | A+ |
| All carriers on IAH–MCO | 3,569 | 83.2% | 80 min | 1.04% | B |
| United Airlines, whole network | 830,825 | 78.8% | 73 min | 1.02% | B |
Across the year
UA 2451 quarter by quarter
UA 2451 did not run the same all year. Its best quarter was Jul–Sep 2025 at 93.3% on time and its weakest Jul–Sep 2026 at 70.2%, a swing of 23 points on roughly 68 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 202530 flights93.3%
- Oct–Dec 202592 flights76.1%
- Jan–Mar 202690 flights83.9%
- Apr–Jun 202680 flights80.0%
- Jul–Sep 202647 flights70.2%
Scale runs 60% to 100%.
By weekday, UA 2451 did best on Wednesday at 95.1% on time and worst on Sunday at 74.5%. Each day rests on about 48 flights, so a gap of 21 points is worth noticing but could still narrow in another year.
Arrival by arrival
How late UA 2451 runs when it is late
UA 2451 often beats the schedule: 105 of 336 completed flights, 31%, arrived 15 minutes or more early. The 68 late arrivals split 15 under half an hour, 28 between 30 and 60 minutes, and 25 an hour or more.
- 15+ min early105 flights31.3%
- Within 15 min163 flights48.5%
- 15–29 min late15 flights4.5%
- 30–59 min late28 flights8.3%
- 1–2 hours late14 flights4.2%
- 2+ hours late11 flights3.3%
Scale runs 0% to 100%.
Share of 336 completed flights by arrival against schedule.
24 of 83 late departures made up the time and arrived on time, 29% of them. 9 flights left on time and still arrived late.
The worst days
Worst days for UA 2451
The latest arrival of the period was on 30 October 2025, 3 hours 25 minutes behind schedule; most of its delay minutes were filed as national airspace system delay. On three of the five worst days the largest share was filed as a late-arriving aircraft.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 30 October 2025 | 3 hours 25 minutes | National Airspace System |
| 28 August 2026 | 3 hours 5 minutes | Late-arriving aircraft |
| 11 March 2026 | 3 hours 1 minute | Late-arriving aircraft |
| 12 July 2026 | 2 hours 37 minutes | Late-arriving aircraft |
| 27 February 2026 | 2 hours 35 minutes | National Airspace System |
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 4,393 reported delay minutes.
- 41%Late-arriving aircraft
- 29%National Airspace System
- 21%Carrier
- 9%Extreme weather
41% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 4,393 reported delay minutes here, that single category outweighs weather by 4 to one. The split is drawn from 4,393 delay minutes reported on UA 2451.
Cancellations are rare at 0.59%, 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
7.4% of arrivals land an hour or more late, close to the national 8.3%, so 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.
The same number turns up on six other city pairs in the data, including ORD to IAH (47), SJC to ORD (47) and EWR to IAH (37), 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. 339 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 79.8% on time with 0.59% cancelled over 339 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 route86.8%
- United Airlines 496 on the same route80.6%
- United Airlines 2245 on the same route94.7%
- United Airlines 1571 on the same route84.5%
- Frontier Airlines 1418 on the same route77.9%
- 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, September 2025 to August 2026. Last updated ; recomputed monthly. How this data is collected.