Flight number record
UA 678
United Airlines · McAllen to Houston
- Route
- MFE → IAH
- Departs
- 07:00
- Flights
- 363
- Period
- September 2025 to August 2026
Historical statistics for September 2025 to August 2026, not live status. For today’s UA 678, check with United Airlines.
UA 678 lands a B+, 6 points better than the national rate of 77.3%. About one flight in six arrives 15 minutes late or worse, and those flights are late by an hour and a half on average. That rests on 363 flights, with a median arrival 7 minutes early.
Set against the rest of the country, UA 678's record is 6 points better than the US average of 77.3%. That gap is worth roughly 64 fewer late arrivals for every thousand flights.
Key figures
On time
83.7%
Arrivals under 15 minutes late, of 361 completed flights
Avg delay
83 min
Across delayed arrivals only, not all flights
Cancelled
0.55%
National rate is 1.89%
1 hour+ late
5.3%
National rate is 8.3%
These figures cover 363 flights between September 2025 and August 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.
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Schedule
When UA 678 flies
UA 678 is scheduled to leave McAllen (MFE) at 07:00 local time and reach Houston (IAH) at 08:19. That slot held for 339 of the 363 scheduled departures in the data, so the figures below describe one steady operation rather than a number that moved around the clock.
- Departs 07:00339 flights93.4%
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 07:00 departure sits in the 5am–8am window. Across every US flight scheduled in that window the on-time rate is 89.3%, and UA 678 runs 6 points worse at 83.7%. 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 678 next to MFE to IAH
Every carrier on MFE to IAH combined arrived on time 80.7% of the time across 737 flights, so UA 678 is 3 points ahead of it. Across its whole network United Airlines managed 78.8%, which this flight beats by 5 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| UA 678thin sample | 363 | 83.7% | 83 min | 0.55% | B+ |
| All United Airlines on MFE–IAH | 409 | 84.5% | 79 min | 0.49% | B+ |
| All carriers on MFE–IAH | 737 | 80.7% | 132 min | 0.68% | B+ |
| United Airlines, whole network | 830,825 | 78.8% | 73 min | 1.02% | B |
Across the year
UA 678 quarter by quarter
UA 678 did not run the same all year. Its best quarter was Jan–Mar 2026 at 89.7% on time and its weakest Apr–Jun 2026 at 75.8%, a swing of 14 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 202530 flights86.7%
- Oct–Dec 202591 flights85.7%
- Jan–Mar 202689 flights89.7%
- Apr–Jun 202691 flights75.8%
- Jul–Sep 202662 flights82.3%
Scale runs 65% to 95%.
By weekday, UA 678 did best on Friday at 90.2% on time and worst on Wednesday at 74.5%. Each day rests on about 52 flights, so a gap of 16 points is worth noticing but could still narrow in another year.
Arrival by arrival
How late UA 678 runs when it is late
UA 678 often beats the schedule: 93 of 361 completed flights, 26%, arrived 15 minutes or more early. The 59 late arrivals split 26 under half an hour, 14 between 30 and 60 minutes, and 19 an hour or more.
- 15+ min early93 flights25.8%
- Within 15 min209 flights57.9%
- 15–29 min late26 flights7.2%
- 30–59 min late14 flights3.9%
- 1–2 hours late9 flights2.5%
- 2+ hours late10 flights2.8%
Scale runs 0% to 100%.
Share of 361 completed flights by arrival against schedule.
Time lost at the gate mostly stays lost. Of 28 departures that left 15 minutes late or more, only 0 made it up before arrival. In the other direction, 31 flights left on time yet arrived 15 minutes late or more, so that delay built up after pushback: in the air, in a holding pattern or on the ground at IAH.
The worst days
Worst days for UA 678
The latest arrival of the period was on 11 May 2026, 14 hours 19 minutes behind schedule; most of its delay minutes were filed as a late-arriving aircraft. The same cause led on three of the five worst days.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 11 May 2026 | 14 hours 19 minutes | Late-arriving aircraft |
| 15 July 2026 | 10 hours 27 minutes | Late-arriving aircraft |
| 22 October 2025 | 5 hours 33 minutes | Late-arriving aircraft |
| 6 June 2026 | 3 hours 23 minutes | Carrier |
| 25 December 2025 | 3 hours 4 minutes | Carrier |
Delay causes
Why UA 678 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 4,869 reported delay minutes.
- 39%Late-arriving aircraft
- 33%National Airspace System
- 28%Carrier
39% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 4,869 reported delay minutes here, that single category outweighs weather by 39 to one. The split is drawn from 4,869 delay minutes reported on UA 678.
Cancellations are rare at 0.55%, 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
5.3% 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 an hour and a half, which a normal layover absorbs.
The same number turns up on three other city pairs in the data, including IAH to LGA (222), SBA to DEN (1) and BTV to DEN (1), but none flew often enough under UA 678 to report a rate for. Carriers move flight numbers between routes, so the figures on this page apply to MFE to IAH only.
One caution: this is a thin sample. 363 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 678
For a booking, read UA 678 as 83.7% on time with 0.55% cancelled over 363 flights. Those are rates from the past twelve months, not a forecast for any particular day.
Related
Where to go next
- MFE to IAH, every carrier and departure
- IAH to MFE, the return direction
- George Bush Intercontinental (IAH) 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.