Carrier route record

OOONT→SLC

SkyWest Airlines · Ontario to Salt Lake City

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 ONT 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 15 points better than the national rate of 77.6%. When something does go wrong the average delay runs an hour and a half. That rests on 307 flights, with a median arrival 13 minutes early.

Set against the rest of the country, SkyWest's ONT to SLC record is 15 points better than the US average of 77.6%. That gap is worth roughly 146 fewer late arrivals for every thousand flights.

On time

92.2%

Arrivals under 15 minutes late, of 306 completed flights

Avg delay

89 min

Across delayed arrivals only, not all flights

Cancelled

0.33%

National rate is 1.81%

Whole route

91.7%

Every carrier on ONT to SLC, 1,239 flights

These figures cover 307 flights between July 2025 and June 2026. The median arrival is 13 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 ONT to SLC

SkyWest flew 307 of the 1,239 flights on ONT to SLC, about 25% of it. Its 92.2% on time is about level with the route as a whole at 91.7%. Ranked by on-time rate it is first of three carriers on the route, where the range runs from SkyWest at 92.2% to Frontier at 86.7%. 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 ONT to SLC
Airline	Flights	On time	Avg delay	Cancelled	Grade
SkyWest Airlines (this page)thin sample	307	92.2%	89 min	0.33%	A+
Delta Air Lines	902	91.7%	83 min	1.11%	A
Frontier Airlinesthin sample	30	86.7%	42 min	0.00%	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.

5am–8am—
8am–11am23 flights—
11am–2pm16 flights—
2pm–5pm116 flights91.3%
5pm–8pm152 flights93.4%
8pm–5am—

Scale runs 85% to 100%. Rows with fewer than 30 flights show a dash.

The 5pm–8pm window is the strongest at 93.4% on time. The full set of windows spans 2 points.

Across the year

SkyWest on ONT to SLC through the year

Jul–Sep 202580 flights88.8%
Oct–Dec 2025107 flights94.3%
Jan–Mar 202629 flights—
Apr–Jun 202691 flights95.6%

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 92.2% on time across 307 flights.

Quarter by quarter SkyWest on ONT to SLC held fairly steady: 88.8% in Jul–Sep 2025, 94.3% in Oct–Dec 2025 and 95.6% in Apr–Jun 2026. A spread of 7 points is about what a sample of this size moves on its own, so the annual figure is a fair summary.

Across the week, Tuesday is the strongest day at 97.9% on time and Friday the weakest at 86.7%. 11 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 82% of the 2,132 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
82%
Extreme weather
14%
National Airspace System
5%

Extreme weather accounts for 14% 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 2.2 times the usual weather exposure. The split is drawn from 2,132 reported delay minutes.

The largest share of delay minutes, 82%, 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 1,738 of the 2,132 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 2.3% 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 94.4% 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 ONT to SLC

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 92.2% 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