Carrier route record

OOONT→SLC

SkyWest Airlines · Ontario to Salt Lake City

Flights: 340
Period: September 2025 to August 2026
Share of route: 27%
Carriers: 3

Historical statistics for September 2025 to August 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 14 points better than the national rate of 77.3%. When something does go wrong the average delay runs an hour and a half. That rests on 340 flights, with a median arrival 13 minutes early.

Set against the rest of the country, SkyWest's ONT to SLC record is 14 points better than the US average of 77.3%. That gap is worth roughly 141 fewer late arrivals for every thousand flights.

On time

91.4%

Arrivals under 15 minutes late, of 339 completed flights

Avg delay

99 min

Across delayed arrivals only, not all flights

Cancelled

0.29%

National rate is 1.89%

Whole route

91.1%

Every carrier on ONT to SLC, 1,239 flights

These figures cover 340 flights between September 2025 and August 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.

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Carrier by carrier

SkyWest against every carrier on ONT to SLC

SkyWest flew 340 of the 1,239 flights on ONT to SLC, about 27% of it. Its 91.4% on time is about level with the route as a whole at 91.1%. Ranked by on-time rate it is first of three carriers on the route, where the range runs from SkyWest at 91.4% 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	340	91.4%	99 min	0.29%	A+
Delta Air Lines	869	91.1%	84 min	1.15%	A
Frontier Airlinesthin sample	30	86.7%	42 min	0.00%	A+

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 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 340 flights.

5am–8am—
8am–11am47 flights100.0%
11am–2pm16 flights—
2pm–5pm99 flights91.8%
5pm–8pm178 flights90.4%
8pm–5am—

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

Book the morning departure. Flights leaving between 8am–11am arrive on time 100.0% of the time, against 90.4% for the evening window. That is 10 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 5pm–8pm window is the busiest, with 178 flights scheduled in it.

Across the year

SkyWest on ONT to SLC through the year

Jul–Sep 202527 flights—
Oct–Dec 2025107 flights94.3%
Jan–Mar 202629 flights—
Apr–Jun 202691 flights95.6%
Jul–Sep 202686 flights89.5%

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 91.4% on time across 340 flights.

Quarter by quarter SkyWest on ONT to SLC held fairly steady: 94.3% in Oct–Dec 2025, 95.6% in Apr–Jun 2026 and 89.5% in Jul–Sep 2026. A spread of 6 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 96.0% on time and Friday the weakest at 87.8%, a spread of 8 points.

Arrival by arrival

How late SkyWest on ONT to SLC runs when it is late

SkyWest on ONT to SLC often beats the schedule: 159 of 339 completed flights, 47%, arrived 15 minutes or more early. The 29 late arrivals split 14 under half an hour, 6 between 30 and 60 minutes, and 9 an hour or more.

15+ min early159 flights46.9%
Within 15 min151 flights44.5%
15–29 min late14 flights4.1%
30–59 min late6 flights1.8%
1–2 hours late4 flights1.2%
2+ hours late5 flights1.5%

Scale runs 0% to 100%.

Share of 339 completed flights by arrival against schedule.

Time lost at the gate mostly stays lost. Of 23 departures that left 15 minutes late or more, only 2 made it up before arrival. 8 flights left on time and still arrived late.

The worst days

Worst days for SkyWest on ONT to SLC

The latest arrival of the period was on 6 September 2025, 14 hours 51 minutes behind schedule; most of its delay minutes were filed as carrier-caused (crew, maintenance, fuelling, baggage). The same cause led on four of the five worst days.

The latest arrivals of SkyWest on ONT to SLC in the period
Date	Arrived late by	Largest filed cause
6 September 2025	14 hours 51 minutes	Carrier
7 July 2026	5 hours 57 minutes	Carrier
17 July 2026	4 hours 37 minutes	Carrier
31 December 2025	4 hours 5 minutes	Extreme weather
26 March 2026	2 hours 55 minutes	Carrier

Delay causes

Why SkyWest runs late on this route

Carrier accounts for 81% of the 2,856 delay minutes carriers reported here, and the remaining four split what is left.

Carrier
81%
Extreme weather
15%
National Airspace System
4%

Extreme weather accounts for 15% 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 2.5 times the usual weather exposure. The split is drawn from 2,856 reported delay minutes.

The largest share of delay minutes, 81%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. It accounts for 2,303 of the 2,856 delay minutes reported here.

Cancellations are rare at 0.29%, 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

Badly late arrivals are rare here: only 2.7% land an hour or more behind schedule, against 8.3% 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.

The return leg runs 93.2% on time across 340 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. 340 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. 340 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 91.4% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 339 completed flights over 12 months sit behind that.

Where to go next

Source: US DOT Bureau of Transportation Statistics, on-time performance data, September 2025 to August 2026. Last updated 22 October 2026; recomputed monthly. How this data is collected.

Key figures