Carrier route record
UASLC→IAH
United Airlines · Salt Lake City to Houston
- Flights
- 878
- Period
- July 2025 to June 2026
- Share of route
- 45%
- Carriers
- 3
Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with United Airlines.
United on SLC to IAH 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 an hour. That rests on 878 flights, with a median arrival 10 minutes early.
Set against the rest of the country, United's SLC to IAH record is 10 points better than the US average of 77.6%. That gap is worth roughly 99 fewer late arrivals for every thousand flights.
Key figures
On time
87.5%
Arrivals under 15 minutes late, of 862 completed flights
Avg delay
67 min
Across delayed arrivals only, not all flights
Cancelled
1.48%
National rate is 1.81%
Whole route
84.7%
Every carrier on SLC to IAH, 1,957 flights
These figures cover 878 flights between July 2025 and June 2026. The median arrival is 10 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.
Carrier by carrier
United against every carrier on SLC to IAH
United flew 878 of the 1,957 flights on SLC to IAH, about 45% of it. Its 87.5% on time is 3 points better than the route as a whole, which runs 84.7%. Ranked by on-time rate it is number two of three carriers on the route, where the range runs from SkyWest at 87.9% to Delta at 82.1%. One of those carriers flew fewer than 365 flights here, so treat their positions as rough.
Only one carrier clears this site's 365-flight floor here, so there is no comparison to draw. The table below is the full picture.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| SkyWest Airlinesthin sample | 68 | 87.9% | 57 min | 1.47% | A |
| United Airlines (this page) | 878 | 87.5% | 67 min | 1.48% | A |
| Delta Air Lines | 1,011 | 82.1% | 81 min | 0.20% | B+ |
Flight by flight
United flight numbers on SLC to IAH
Departure window
When United runs best on this route
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 12 points, against half a point between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am364 flights93.0%
- 8am–11am18 flights—
- 11am–2pm367 flights81.3%
- 2pm–5pm129 flights87.4%
- 5pm–8pm—
- 8pm–5am—
Scale runs 75% to 100%. Rows with fewer than 30 flights show a dash.
The weak window here is the middle of the day, not the evening: 11am–2pm runs 81.3% on time against 93.0% for 5am–8am. That shape usually means a departure bank rather than an accumulating delay, so the recovery later in the afternoon is real rather than noise. The 11am–2pm window is the busiest, with 367 flights scheduled in it.
Across the year
United on SLC to IAH through the year
August is the worst month at 75.7% on time, 19 points below December, the best at 94.7%. Summer afternoon convection and peak-season schedules land on the same weeks every year, so this is a pattern you can book around rather than a run of bad luck. January was the busiest month here, with 98 flights.
Across the week, Thursday is the strongest day at 89.7% on time and Wednesday the weakest at 83.7%. 6 points is a smaller lever than departure hour, but it is free.
Delay causes
Why United runs late on this route
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 7,229 reported delay minutes.
- 35%Carrier
- 35%National Airspace System
- 30%Late-arriving aircraft
- 0%Extreme weather
The largest share of delay minutes, 35%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. Unlike weather, that is a management outcome, and it is the category where the gap between two carriers on the same schedule is genuinely earned. It accounts for 2,515 of the 7,229 delay minutes reported here. The split is drawn from 7,229 reported delay minutes.
35% 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 2,495 minutes out of 7,229, against a national NAS share of 21%.
Cancellations sit at 1.48% against a national 1.81%, which is ordinary. Diversions add another 0.34%.
Connections and stage length
What a delay here costs
Badly late arrivals are rare here: only 3.6% 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 1,195 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 return leg is a different operation and performs like one: it runs 82.9% on time across 879 flights, 5 points below this direction. Departure banks, aircraft rotations and the congestion at each end all differ, so scoring the two directions together would average away a real 5 points of difference.
One caution: this is a thin sample. 878 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 United on SLC to IAH
Put together: treat all of this as provisional. 878 flights over twelve months is enough to clear this site's floor and not enough to be confident to better than a couple of points. The 87.5% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 862 completed flights over 12 months sit behind that.
Related
Where to go next
- SLC to IAH, every carrier
- United on IAH to SLC, the return leg
- Delta Air Lines on SLC to IAH82.1%
- United Airlines network-wide record
- Salt Lake City International (SLC) delay statistics
- George Bush Intercontinental (IAH) delay statistics
- The best time of day to fly, according to 7.04 million flight records
- Worst months to fly in the US, ranked by the data
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.