Carrier route record

UALAX→SLC

United Airlines · Los Angeles to Salt Lake City

Flights: 149
Period: July 2025 to June 2026
Share of route: 4%
Carriers: 6

Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with United Airlines.

United on LAX to SLC 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 77.6%. When something does go wrong the average delay runs about an hour. That rests on 149 flights. The strongest carrier on the route with a full sample, SkyWest Airlines, flew 691 at 89.6% on time.

SkyWest Airlines is the most reliable of the four carriers covered here at 89.6% on time across 691 flights.

On time

88.6%

Arrivals under 15 minutes late, of 149 completed flights

Avg delay

65 min

Across delayed arrivals only, not all flights

Cancelled

0.00%

National rate is 1.81%

Whole route

87.7%

Every carrier on LAX to SLC, 4,144 flights

These figures cover 149 flights between July 2025 and June 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.

Carrier by carrier

United against every carrier on LAX to SLC

United flew 149 of the 4,144 flights on LAX to SLC, about 4% of it. Its 88.6% on time is about level with the route as a whole at 87.7%. Ranked by on-time rate it is number three of six carriers on the route, where the range runs from Spirit at 90.9% to Southwest at 81.7%. One of those carriers flew fewer than 365 flights here, so treat their positions as rough.

The choice of carrier is not cosmetic here. SkyWest Airlines arrives on time 89.6% of the time; Southwest Airlines manages 81.7%. Sample sizes sit next to every figure, because a two-point gap across 374 flights means less than a ten-point one.

On-time performance by carrier on LAX to SLC
Airline	Flights	On time	Avg delay	Cancelled	Grade
Spirit Airlinesthin sample	23	90.9%	29 min	4.35%	A−
SkyWest Airlines	691	89.6%	87 min	0.00%	A+
United Airlines (this page)thin sample	149	88.6%	65 min	0.00%	A+
Delta Air Lines	2,451	88.5%	79 min	0.41%	A+
Frontier Airlines	456	85.2%	76 min	0.88%	A+
Southwest Airlines	374	81.7%	46 min	0.53%	B+

SkyWest leads Southwest by 8 points. Real, but small enough that a better departure time on the weaker carrier can outweigh it.

Departure window

When United runs best on this route

Departure time is the single lever a traveller controls, and it moves the odds more than most people expect. Each bar below is the on-time rate for flights scheduled to leave inside that window, across 149 flights.

There are not enough flights in each departure window to split United's LAX to SLC record by time of day without the percentages moving on noise. The headline rate of 88.6% is the reliable figure here.

Across the year

United on LAX to SLC through the year

Oct–Dec 202514 flights—
Jan–Mar 202685 flights90.6%
Apr–Jun 202650 flights96.0%

Scale runs 80% to 100%. Rows with fewer than 30 flights show a dash.

Monthly volumes are too low here to break the year into twelve reliable readings. What the twelve-month total says is 88.6% on time across 149 flights.

Split by quarter, United on LAX to SLC logged 14 flights in Oct–Dec 2025, 85 flights in Jan–Mar 2026 and 50 flights in Apr–Jun 2026. Fewer than three of those quarters carried the 30 completed flights this site needs before printing a rate, so the 88.6% annual figure is the one to use.

Delay causes

Why United runs late on this route

One category carries most of the weight here. Late-arriving aircraft accounts for 56% of the 1,110 delay minutes carriers reported, and the remaining four split what is left. The split is by minutes rather than by flights, so a few very long delays count for as much as many short ones.

Late-arriving aircraft
56%
Carrier
44%

56% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. That is a cascade, and cascades start small and grow through the day. Across 1,110 reported delay minutes here, that single category outweighs weather by 56 to one. It is the strongest argument for booking the first departure of the morning, when the aircraft has been sitting at the gate overnight with nothing to inherit. The split is drawn from 1,110 reported delay minutes.

The largest share of delay minutes, 44%, 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 484 of the 1,110 delay minutes reported here.

Cancellations are rare at 0.00%, below the national 1.81% and low enough to earn the plus on the grade. Almost no flights are called off; the risk here is arriving late, not not arriving.

Connections and stage length

What a delay here costs

Badly late arrivals are rare here: only 4.7% 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 590 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 91.9% on time across 148 flights, 3 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 3 points of difference.

One caution: this is a thin sample. 149 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 LAX to SLC

Put together: treat all of this as provisional. 149 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 88.6% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 149 completed flights over 12 months sit behind that.

Where to go next

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