Carrier route record

OOSLC→ONT

SkyWest Airlines · Salt Lake City to Ontario

Flights: 307
Period: July 2025 to June 2026
Share of route: 25%
Carriers: 3

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

SkyWest on SLC to ONT earns an A+. Nearly every flight arrives inside the 15-minute window the DOT uses to define an on-time arrival, which puts it 17 points better than the national rate of 77.6%. When something does go wrong the average delay runs roughly 50 minutes. That rests on 307 flights, with a median arrival 8 minutes early.

Set against the rest of the country, SkyWest's SLC to ONT record is 17 points better than the US average of 77.6%. That gap is worth roughly 168 fewer late arrivals for every thousand flights.

On time

94.4%

Arrivals under 15 minutes late, of 306 completed flights

Avg delay

52 min

Across delayed arrivals only, not all flights

Cancelled

0.33%

National rate is 1.81%

Whole route

89.5%

Every carrier on SLC to ONT, 1,239 flights

These figures cover 307 flights between July 2025 and June 2026. The median arrival is 8 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

SkyWest against every carrier on SLC to ONT

SkyWest flew 307 of the 1,239 flights on SLC to ONT, about 25% of it. Its 94.4% on time is 5 points better than the route as a whole, which runs 89.5%. Ranked by on-time rate it is first of three carriers on the route, where the range runs from SkyWest at 94.4% to Delta at 87.7%. 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.

On-time performance by carrier on SLC to ONT
Airline	Flights	On time	Avg delay	Cancelled	Grade
SkyWest Airlines (this page)thin sample	307	94.4%	52 min	0.33%	A+
Frontier Airlinesthin sample	30	93.1%	101 min	3.33%	A−
Delta Air Lines	902	87.7%	64 min	1.11%	A

Departure window

When SkyWest 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 307 flights.

There are not enough flights in each departure window to split SkyWest's SLC to ONT record by time of day without the percentages moving on noise. The headline rate of 94.4% is the reliable figure here.

Across the year

SkyWest on SLC to ONT through the year

Jul–Sep 202580 flights93.8%
Oct–Dec 2025107 flights96.2%
Jan–Mar 202629 flights—
Apr–Jun 202691 flights92.3%

Scale runs 85% 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 94.4% on time across 307 flights.

Quarter by quarter SkyWest on SLC to ONT held fairly steady: 93.8% in Jul–Sep 2025, 96.2% in Oct–Dec 2025 and 92.3% in Apr–Jun 2026. A spread of 4 points is about what a sample of this size moves on its own, so the annual figure is a fair summary.

Across the week, Saturday is the strongest day at 100.0% on time and Friday the weakest at 91.1%. 9 points is a smaller lever than departure hour, but it is free.

Delay causes

Why SkyWest runs late on this route

One category carries most of the weight here. Carrier accounts for 58% of the 884 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.

Carrier
58%
Extreme weather
26%
National Airspace System
15%

Extreme weather accounts for 26% of delay minutes, well above the single-digit share typical across the system. Weather delays are lumpy: they arrive as whole bad days rather than as a steady drag, so the monthly strip above is the more useful view of the risk. The national share is 6%, so this operation carries roughly 4.2 times the usual weather exposure. The split is drawn from 884 reported delay minutes.

The largest share of delay minutes, 58%, 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 514 of the 884 delay minutes reported here.

Cancellations are rare at 0.33%, 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 stage length

What a delay here costs

Badly late arrivals are rare here: only 1.3% 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 558 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 runs 92.2% on time across 307 flights, within 2 points of this direction. The two legs are scored separately because they usually differ; on this city pair they happen not to.

One caution: this is a thin sample. 307 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 SkyWest on SLC to ONT

Put together: treat all of this as provisional. 307 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 94.4% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 306 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