Carrier route record
UAIAH→SLC
United Airlines · Houston to Salt Lake City
- Flights
- 856
- Period
- September 2025 to August 2026
- Share of route
- 44%
- Carriers
- 3
Historical statistics for September 2025 to August 2026, not live status. For today’s flights, check with United Airlines.
United on IAH to SLC 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 about an hour on average. That rests on 856 flights, with a median arrival 6 minutes early.
Set against the rest of the country, United's IAH to SLC record is 6 points better than the US average of 77.3%. That gap is worth roughly 63 fewer late arrivals for every thousand flights.
Key figures
On time
83.6%
Arrivals under 15 minutes late, of 850 completed flights
Avg delay
64 min
Across delayed arrivals only, not all flights
Cancelled
0.47%
National rate is 1.89%
Whole route
83.4%
Every carrier on IAH to SLC, 1,932 flights
These figures cover 856 flights between September 2025 and August 2026. The median arrival is 6 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.
Fare search by Aviasales, a Travelpayouts partner. Booking through it may earn this site a commission at no cost to you; it changes no figure here.
Carrier by carrier
United against every carrier on IAH to SLC
United flew 856 of the 1,932 flights on IAH to SLC, about 44% of it. Its 83.6% on time is about level with the route as a whole at 83.4%. Ranked by on-time rate it is first of three carriers on the route, where the range runs from United at 83.6% to SkyWest at 79.7%. 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 |
|---|---|---|---|---|---|
| United Airlines (this page) | 856 | 83.6% | 64 min | 0.47% | B+ |
| Delta Air Lines | 1,016 | 83.3% | 90 min | 0.39% | B+ |
| SkyWest Airlinesthin sample | 60 | 79.7% | 67 min | 1.67% | B |
Flight by flight
United flight numbers on IAH to SLC
Timetable by Aviasales, a Travelpayouts partner. Booking through it may earn this site a commission at no cost to you; it changes no figure here.
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 15 points, against half a point between the best and worst carrier.
- 5am–8am—
- 8am–11am358 flights87.0%
- 11am–2pm117 flights92.3%
- 2pm–5pm19 flights—
- 5pm–8pm—
- 8pm–5am362 flights76.9%
Scale runs 70% to 100%. Rows with fewer than 30 flights show a dash.
The best window here is not the first bank but the 11am–2pm slot at 92.3% on time, ahead of 8pm–5am at 76.9%. Where the curve peaks mid-day rather than at dawn, the constraint is usually congestion at one end rather than the aircraft's own rotation. The 8pm–5am window is the busiest, with 362 flights scheduled in it.
Across the year
United on IAH to SLC through the year
June is the worst month at 71.4% on time, 21 points below February, the best at 92.3%. 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, Saturday is the strongest day at 88.1% on time and Sunday the weakest at 80.9%, a spread of 7 points.
Arrival by arrival
How late United on IAH to SLC runs when it is late
United on IAH to SLC often beats the schedule: 239 of 850 completed flights, 28%, arrived 15 minutes or more early. The 139 late arrivals split 42 under half an hour, 53 between 30 and 60 minutes, and 44 an hour or more.
- 15+ min early239 flights28.1%
- Within 15 min472 flights55.5%
- 15–29 min late42 flights4.9%
- 30–59 min late53 flights6.2%
- 1–2 hours late27 flights3.2%
- 2+ hours late17 flights2.0%
Scale runs 0% to 100%.
Share of 850 completed flights by arrival against schedule.
A late pushback is often recovered here: of 160 departures that left 15 minutes late or more, 51 still arrived on time. 30 flights left on time and still arrived late.
The worst days
Worst days for United on IAH to SLC
The latest arrival of the period was on 10 August 2026, 5 hours 54 minutes behind schedule; most of its delay minutes were filed as a late-arriving aircraft. Three of the five worst days fell in August 2026.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 10 August 2026 | 5 hours 54 minutes | Late-arriving aircraft |
| 12 August 2026 | 5 hours 32 minutes | Carrier |
| 7 March 2026 | 5 hours 9 minutes | Late-arriving aircraft |
| 9 August 2026 | 4 hours 6 minutes | Late-arriving aircraft |
| 4 March 2026 | 3 hours 38 minutes | Carrier |
Delay causes
Why United runs late on this route
Late-arriving aircraft accounts for 50% of the 8,860 delay minutes carriers reported here, and the remaining four split what is left.
- 50%Late-arriving aircraft
- 32%Carrier
- 16%National Airspace System
- 2%Extreme weather
50% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 8,860 reported delay minutes here, that single category outweighs weather by 22 to one. The split is drawn from 8,860 reported delay minutes.
Cancellations are rare at 0.47%, 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 stage length
What a delay here costs
5.2% 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 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.
The return leg is a different operation and performs like one: it runs 89.5% on time across 854 flights, 6 points above 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 6 points of difference.
One caution: this is a thin sample. 856 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 IAH to SLC
Put together: treat all of this as provisional. 856 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 83.6% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 850 completed flights over 12 months sit behind that.
Related
Where to go next
- IAH to SLC, every carrier
- United on SLC to IAH, the return leg
- Delta Air Lines on IAH to SLC83.3%
- United Airlines network-wide record
- George Bush Intercontinental (IAH) delay statistics
- Salt Lake City International (SLC) delay statistics
- Why the first flight of the morning is statistically safest
- The best time of day to fly, according to 7.05 million flight records
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.