Flight number record
UA 1799
United Airlines · Houston to Las Vegas
- Route
- IAH → LAS
- Departs
- 09:45
- Flights
- 365
- Period
- September 2025 to August 2026
Historical statistics for September 2025 to August 2026, not live status. For today’s UA 1799, check with United Airlines.
UA 1799 earns an A+. Close to nine flights in ten arrive inside the 15-minute window the DOT uses to define an on-time arrival, which puts it 11 points better than the national rate of 77.3%. When something does go wrong the average delay runs roughly 55 minutes. That rests on 365 flights, with a median arrival 12 minutes early.
Set against the rest of the country, UA 1799's record is 11 points better than the US average of 77.3%. That gap is worth roughly 111 fewer late arrivals for every thousand flights.
Key figures
On time
88.4%
Arrivals under 15 minutes late, of 363 completed flights
Avg delay
53 min
Across delayed arrivals only, not all flights
Cancelled
0.55%
National rate is 1.89%
1 hour+ late
2.5%
National rate is 8.3%
These figures cover 365 flights between September 2025 and August 2026. The median arrival is 12 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 1799 flies
UA 1799 flies IAH to LAS without a single fixed slot. Its most common scheduled departure was 09:45, used on 82 of 365 flights, with 10:55 (77 flights) and 09:46 (68 flights) next.
- Departs 09:4582 flights22.5%
- Departs 10:5577 flights21.1%
- Departs 09:4668 flights18.6%
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 09:45 departure sits in the 8am–11am window. Across every US flight scheduled in that window the on-time rate is 83.9%, and UA 1799 runs 5 points better at 88.4%. 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 1799 next to IAH to LAS
Every carrier on IAH to LAS combined arrived on time 82.8% of the time across 3,409 flights, so UA 1799 is 6 points ahead of it. United flew 2,598 flights on the same city pair under all its flight numbers, including this one, and those ran 85.2% on time. Across its whole network United Airlines managed 78.8%, which this flight beats by 10 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| UA 1799 | 365 | 88.4% | 53 min | 0.55% | A+ |
| All United Airlines on IAH–LAS | 2,598 | 85.2% | 60 min | 0.27% | A+ |
| All carriers on IAH–LAS | 3,409 | 82.8% | 71 min | 0.85% | B+ |
| United Airlines, whole network | 830,825 | 78.8% | 73 min | 1.02% | B |
Across the year
UA 1799 quarter by quarter
UA 1799 did not run the same all year. Its best quarter was Jan–Mar 2026 at 95.5% on time and its weakest Apr–Jun 2026 at 79.1%, a swing of 16 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 flights93.3%
- Oct–Dec 202592 flights89.1%
- Jan–Mar 202690 flights95.5%
- Apr–Jun 202691 flights79.1%
- Jul–Sep 202662 flights88.7%
Scale runs 70% to 100%.
By weekday, UA 1799 ranged from 84.3% on Tuesday to 92.3% on Wednesday. With about 52 flights behind each day, a spread of 8 points is inside normal variation, so the day you fly is not worth changing for this flight.
Arrival by arrival
How late UA 1799 runs when it is late
UA 1799 often beats the schedule: 150 of 363 completed flights, 41%, arrived 15 minutes or more early. The 42 late arrivals split 17 under half an hour, 16 between 30 and 60 minutes, and 9 an hour or more.
- 15+ min early150 flights41.3%
- Within 15 min171 flights47.1%
- 15–29 min late17 flights4.7%
- 30–59 min late16 flights4.4%
- 1–2 hours late3 flights0.8%
- 2+ hours late6 flights1.7%
Scale runs 0% to 100%.
Share of 363 completed flights by arrival against schedule.
11 of 47 late departures made up the time and arrived on time, 23% of them. Only 6 left on time and still arrived late.
The worst days
Worst days for UA 1799
The latest arrival of the period was on 10 August 2026, 3 hours 45 minutes behind schedule; most of its delay minutes were filed as carrier-caused (crew, maintenance, fuelling, baggage). The same cause led on three of the five worst days.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 10 August 2026 | 3 hours 45 minutes | Carrier |
| 15 June 2026 | 2 hours 52 minutes | Extreme weather |
| 13 July 2026 | 2 hours 33 minutes | Carrier |
| 7 July 2026 | 2 hours 27 minutes | Late-arriving aircraft |
| 14 October 2025 | 2 hours 23 minutes | Carrier |
Delay causes
Why UA 1799 runs late
Carrier accounts for 43% of the 2,239 delay minutes carriers reported here, and the remaining four split what is left.
- 43%Carrier
- 26%Late-arriving aircraft
- 24%National Airspace System
- 7%Extreme weather
The largest share of delay minutes, 43%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. It accounts for 963 of the 2,239 delay minutes reported here. The split is drawn from 2,239 delay minutes reported on UA 1799.
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
Badly late arrivals are rare here: only 2.5% land an hour or more behind schedule, against 8.3% nationally. Connections built on this flight are about as safe as US domestic connections get, though a cancelled flight still ignores every layover you give it.
The 1,222 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.
UA 1799 is not only a IAH to LAS flight. It also flew LAS to SFO (288 flights, 52.8% on time) often enough to be scored on its own. Airlines attach one number to several legs of an aircraft's day, and each leg keeps its own record here, so check which city pair is on your booking before reading a rate.
One caution: this is a thin sample. 365 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.
| Also flown as | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| LAS to SFOthin sample | 288 | 52.8% | 64 min | 0.69% | F+ |
What to do with this
Booking UA 1799
For a booking, UA 1799 has one of the better records a US domestic flight can show: 88.4% on time and 0.55% cancelled. That is a base rate, not a promise about any single day.
Related
Where to go next
- IAH to LAS, every carrier and departure
- LAS to IAH, the return direction
- United Airlines 1971 on the same route85.4%
- United Airlines 1264 on the same route95.1%
- United Airlines 1524 on the same route89.2%
- George Bush Intercontinental (IAH) delay statistics
- Harry Reid International (LAS) 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
- The best time of day to fly, according to 7.05 million flight records
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.