Flight number record

UA 1799

United Airlines · Houston to Las Vegas

Route: IAH → LAS
Departs: 09:45
Flights: 365
Period: July 2025 to June 2026

Historical statistics for July 2025 to June 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 10 points better than the national rate of 77.6%. When something does go wrong the average delay runs about 40 minutes. That rests on 365 flights, with a median arrival 11 minutes early.

Set against the rest of the country, UA 1799's record is 10 points better than the US average of 77.6%. That gap is worth roughly 103 fewer late arrivals for every thousand flights.

On time

87.9%

Arrivals under 15 minutes late, of 363 completed flights

Avg delay

41 min

Across delayed arrivals only, not all flights

Cancelled

0.55%

National rate is 1.81%

1 hour+ late

1.7%

National rate is 8.1%

These figures cover 365 flights between July 2025 and June 2026. The median arrival is 11 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 1799 flies

UA 1799 flies IAH to LAS without a single fixed slot. Its most common scheduled departure was 09:45, used on 137 of 365 flights, with 09:46 (68 flights) and 09:30 (48 flights) next. Carriers retime flights through the season, so the rates here blend slightly different positions in the aircraft's day.

Departs 09:45137 flights37.5%
Departs 09:4668 flights18.6%
Departs 09:3048 flights13.2%

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 09:45 departure sits in the 8am–11am window. Across every US flight scheduled in that window the on-time rate is 84.1%, and UA 1799 runs 4 points better at 87.9%. Early departures usually start with an aircraft that has not flown yet that day, which is most of why the window does well.

Against the route

UA 1799 next to IAH to LAS

Every carrier on IAH to LAS combined arrived on time 82.4% of the time across 3,457 flights, so UA 1799 is 6 points ahead of it. United flew 2,602 flights on the same city pair under all its flight numbers, including this one, and those ran 83.9% on time. Across its whole network United Airlines managed 79.0%, which this flight beats by 9 points.

UA 1799 against its route and carrier
Compared with	Flights	On time	Avg delay	Cancelled	Grade
UA 1799	365	87.9%	41 min	0.55%	A+
All United Airlines on IAH–LAS	2,602	83.9%	59 min	0.38%	B+
All carriers on IAH–LAS	3,457	82.4%	72 min	0.81%	B+
United Airlines, whole network	821,041	79.0%	72 min	1.01%	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 91 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 202592 flights88.0%
Oct–Dec 202592 flights89.1%
Jan–Mar 202690 flights95.5%
Apr–Jun 202691 flights79.1%

Scale runs 70% to 100%. Rows with fewer than 30 flights show a dash.

By weekday, UA 1799 ranged from 84.6% on Thursday 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.

Delay causes

Why UA 1799 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 1,803 reported delay minutes.

National Airspace System
34%
Carrier
34%
Late-arriving aircraft
25%
Extreme weather
8%

34% of delay minutes are charged to the National Airspace System: air traffic volume, runway configuration, ground stops. No carrier can price its way out of that, which is why airport choice moves the number here more than carrier choice does. That is 608 minutes out of 1,803, against a national NAS share of 21%. The split is drawn from 1,803 delay minutes reported on UA 1799.

Cancellations are rare at 0.55%, 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

Badly late arrivals are rare here: only 1.7% land an hour or more behind schedule, against 8.1% 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. 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 nine other city pairs in the data, including LAS to SFO (239), SFO to SBA (41) and ORD to IAH (41), but none flew often enough under UA 1799 to report a rate for. Carriers move flight numbers between routes, so the figures on this page apply to IAH to LAS only.

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.

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: 87.9% on time and 0.55% cancelled. That is a base rate, not a promise about any single day.

Where to go next

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.

Key figures