Carrier route record

OOSLC→ONT

SkyWest Airlines · Salt Lake City to Ontario

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 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 16 points better than the national rate of 77.3%. When something does go wrong the average delay runs about an hour. That rests on 340 flights, with a median arrival 8 minutes early.

Set against the rest of the country, SkyWest's SLC to ONT record is 16 points better than the US average of 77.3%. That gap is worth roughly 159 fewer late arrivals for every thousand flights.

On time

93.2%

Arrivals under 15 minutes late, of 339 completed flights

Avg delay

62 min

Across delayed arrivals only, not all flights

Cancelled

0.29%

National rate is 1.89%

Whole route

88.9%

Every carrier on SLC to ONT, 1,239 flights

These figures cover 340 flights between September 2025 and August 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.

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Carrier by carrier

SkyWest against every carrier on SLC to ONT

SkyWest flew 340 of the 1,239 flights on SLC to ONT, about 27% of it. Its 93.2% on time is 4 points better than the route as a whole, which runs 88.9%. Ranked by on-time rate it is first of three carriers on the route, where the range runs from SkyWest at 93.2% to Delta at 87.1%. 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	340	93.2%	62 min	0.29%	A+
Frontier Airlinesthin sample	30	93.1%	101 min	3.33%	A−
Delta Air Lines	869	87.1%	60 min	1.04%	A

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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 flights97.9%
11am–2pm16 flights—
2pm–5pm277 flights92.4%
5pm–8pm—
8pm–5am—

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

The early departures do better, though not dramatically: 97.9% on time for the 8am–11am window against 92.4% for 2pm–5pm. Worth taking if the schedule allows, not worth an extra connection. The 2pm–5pm window is the busiest, with 277 flights scheduled in it.

Across the year

SkyWest on SLC to ONT through the year

Jul–Sep 202527 flights—
Oct–Dec 2025107 flights96.2%
Jan–Mar 202629 flights—
Apr–Jun 202691 flights92.3%
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 93.2% on time across 340 flights.

Quarter by quarter SkyWest on SLC to ONT held fairly steady: 96.2% in Oct–Dec 2025, 92.3% in Apr–Jun 2026 and 89.5% in Jul–Sep 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 96.0% on time and Friday the weakest at 89.8%, a spread of 6 points.

Arrival by arrival

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

SkyWest on SLC to ONT often beats the schedule: 99 of 339 completed flights, 29%, arrived 15 minutes or more early. The 23 late arrivals split 7 under half an hour, 10 between 30 and 60 minutes, and 6 an hour or more.

15+ min early99 flights29.2%
Within 15 min217 flights64.0%
15–29 min late7 flights2.1%
30–59 min late10 flights2.9%
1–2 hours late4 flights1.2%
2+ hours late2 flights0.6%

Scale runs 0% to 100%.

Share of 339 completed flights by arrival against schedule.

A late pushback is often recovered here: of 27 departures that left 15 minutes late or more, 9 still arrived on time. Only 5 left on time and still arrived late.

The worst days

Worst days for SkyWest on SLC to ONT

The latest arrival of the period was on 17 July 2026, 4 hours 53 minutes behind schedule; most of its delay minutes were filed as carrier-caused (crew, maintenance, fuelling, baggage). Three of the five worst days fell in July 2026.

The latest arrivals of SkyWest on SLC to ONT in the period
Date	Arrived late by	Largest filed cause
17 July 2026	4 hours 53 minutes	Carrier
26 March 2026	3 hours 21 minutes	Extreme weather
3 December 2025	1 hour 48 minutes	National Airspace System
12 July 2026	1 hour 39 minutes	Extreme weather
11 July 2026	1 hour 35 minutes	Carrier

Delay causes

Why SkyWest runs late on this route

Carrier accounts for 64% of the 1,423 delay minutes carriers reported here, and the remaining four split what is left.

Carrier
64%
Extreme weather
23%
National Airspace System
13%

Extreme weather accounts for 23% 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 3.8 times the usual weather exposure. The split is drawn from 1,423 reported delay minutes.

The largest share of delay minutes, 64%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. It accounts for 910 of the 1,423 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 1.8% 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 91.4% 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 SLC to ONT

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 93.2% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 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